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    <title>Forem: Anup Karanjkar</title>
    <description>The latest articles on Forem by Anup Karanjkar (@akaranjkar08).</description>
    <link>https://forem.com/akaranjkar08</link>
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      <title>Forem: Anup Karanjkar</title>
      <link>https://forem.com/akaranjkar08</link>
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    <item>
      <title>Claude Code 2.1 Agent View &amp; /goal: Autonomous Dev Guide 2026</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Sat, 23 May 2026 00:15:55 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/claude-code-21-agent-view-goal-autonomous-dev-guide-2026-31hk</link>
      <guid>https://forem.com/akaranjkar08/claude-code-21-agent-view-goal-autonomous-dev-guide-2026-31hk</guid>
      <description>&lt;p&gt;&lt;strong&gt;I let Claude Code run unsupervised for three hours last Wednesday. It wrote 847 lines of test coverage, debugged six failing tests, and stopped exactly when the conditions I set were met — without me touching the keyboard once. That is what the /goal command does. Combine it with Agent View, the new session dashboard that shipped in v2.1.139 on May 19, 2026, and you have the closest thing to a true autonomous coding partner the CLI has ever shipped.&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;The short version: &lt;code&gt;claude agents&lt;/code&gt; gives you a live dashboard of every session — running, blocked, or done. &lt;code&gt;/goal &amp;lt;condition&amp;gt;&lt;/code&gt; sets a completion target and Claude loops across turns until it is met. Background sessions with &lt;code&gt;--bg&lt;/code&gt; let those loops run without blocking your terminal. This combination turns Claude Code from an interactive assistant into something closer to a scheduled background worker that asks for help only when genuinely stuck.&lt;/p&gt;

&lt;h2&gt;
  
  
  What Shipped in v2.1.139 (And What Came After)
&lt;/h2&gt;

&lt;p&gt;The May 19 release was dense. Agent View and /goal were the headliners, but the two weeks of point releases that followed added features that change how you configure and automate agents. Here is the full picture:&lt;/p&gt;

&lt;div class="table-wrapper-paragraph"&gt;&lt;table&gt;
&lt;thead&gt;
&lt;tr&gt;
&lt;th&gt;Version&lt;/th&gt;
&lt;th&gt;Feature&lt;/th&gt;
&lt;th&gt;What It Does&lt;/th&gt;
&lt;/tr&gt;
&lt;/thead&gt;
&lt;tbody&gt;
&lt;/tbody&gt;
&lt;/table&gt;&lt;/div&gt;

&lt;p&gt;| 2.1.139 | Agent View, /goal | Session dashboard; completion-driven loops |&lt;/p&gt;

&lt;p&gt;| 2.1.140 | Agent hook types | Stop/SubagentStop hooks for agent frontmatter |&lt;/p&gt;

&lt;p&gt;| 2.1.142 | New session flags | --add-dir, --settings, --mcp-config, --permission-mode |&lt;/p&gt;

&lt;p&gt;| 2.1.143 | Worktree isolation toggle | bgIsolation: "none" for repos where worktrees break |&lt;/p&gt;

&lt;p&gt;| 2.1.144 | /resume in agent view | Background sessions appear with bg tag; resume by ID |&lt;/p&gt;

&lt;p&gt;| 2.1.145 | claude agents --json | JSON output for tmux, status bars, scripting |&lt;/p&gt;

&lt;p&gt;| 2.1.147 | /code-review | Renamed from /simplify; reports correctness bugs at chosen effort level |&lt;/p&gt;

&lt;p&gt;| 2.1.149 | /usage breakdown | Per-category costs: skills, subagents, plugins, MCP |&lt;/p&gt;

&lt;p&gt;The version cadence tells you something: Anthropic is shipping against real developer feedback. The worktree isolation fix in 2.1.143 — adding &lt;code&gt;bgIsolation: "none"&lt;/code&gt; for repos where git worktrees are impractical — was not a planned feature. It was a direct response to production blockers. The /resume functionality expanding to Agent View in 2.1.144 filled an obvious gap that the initial launch left open. This is the engineering culture at Anthropic: drop the headline, then fill the missing pieces fast.&lt;/p&gt;

&lt;h2&gt;
  
  
  Agent View: The Session Dashboard You Have Been Waiting For
&lt;/h2&gt;

&lt;p&gt;Run &lt;code&gt;claude agents&lt;/code&gt; from any terminal and you get a single live view of every Claude Code session: which ones are running, which are blocked waiting for your input, and which have finished. The count of sessions awaiting input appears in your terminal tab title — meaning you can see at a glance how many agents need attention without switching context.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="c"&gt;# Open the agent view dashboard&lt;/span&gt;
claude agents

&lt;span class="c"&gt;# Scope it to a specific project directory&lt;/span&gt;
claude agents &lt;span class="nt"&gt;--cwd&lt;/span&gt; ./my-project

&lt;span class="c"&gt;# Output as JSON for scripting (tmux, status bars, monitoring)&lt;/span&gt;
claude agents &lt;span class="nt"&gt;--json&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Inside the dashboard, four keyboard shortcuts do most of the work. &lt;strong&gt;Ctrl+T&lt;/strong&gt; pins a background session — pinned sessions stay alive when idle and auto-restart after Claude Code updates instead of requiring manual relaunch. &lt;strong&gt;Ctrl+R&lt;/strong&gt; renames a session to something human-readable. The &lt;strong&gt;left arrow key&lt;/strong&gt; detaches or closes a session while preserving its state. And &lt;strong&gt;v&lt;/strong&gt; opens the session directly in your editor.&lt;/p&gt;

&lt;p&gt;The session state preservation is the part that matters most in practice. When you detach with the left arrow or background a session with &lt;code&gt;/bg&lt;/code&gt;, it preserves the model, effort level, permission mode, MCP servers, and settings you configured. In earlier Claude Code versions, detaching and resuming a session sometimes reverted to defaults. That regression is gone as of 2.1.142.&lt;/p&gt;

&lt;p&gt;One subtle improvement: sessions launched from Agent View respect the &lt;code&gt;permissions.defaultMode&lt;/code&gt; from your settings.json. If your project settings say &lt;code&gt;auto&lt;/code&gt;, agent view sessions inherit that without you passing a flag every time. Small change, large day-to-day impact.&lt;/p&gt;

&lt;h2&gt;
  
  
  /goal: Tell Claude When It Is Done
&lt;/h2&gt;

&lt;p&gt;The /goal command is deceptively simple. You set a completion condition. Claude works across turns until that condition is met, then stops.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;# In an interactive Claude Code session
/goal Write unit tests covering 95% of the authentication module

# Compound conditions work too
/goal Implement OAuth2 login with Google and GitHub. All existing tests must pass. No TypeScript errors.
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;While a goal is active, a live overlay panel shows elapsed time, number of turns completed, and cumulative token count. The overlay runs in real time without blocking your ability to type — you can interact with the session while Claude is working if you need to redirect it or provide context it is missing.&lt;/p&gt;

&lt;p&gt;What makes /goal different from just giving Claude a task in a single message is that it creates a controlled loop. Claude writes code, runs tests, inspects failures, revises the code, and runs tests again — automatically, across as many turns as the goal requires. The completion condition is checked after each cycle. This is not a new capability in the underlying model; it is a harness change that lets the model apply its existing tool-use and reasoning capabilities over a longer trajectory without requiring you to manually re-prompt it.&lt;/p&gt;

&lt;p&gt;I used /goal to write a Zod schema validation test suite covering edge cases I had been putting off for weeks. The goal ran for 41 minutes and 23 turns. It found three input patterns my initial schemas did not handle and fixed them before stopping. Total cost: $0.43 in API tokens according to /usage. That 41 minutes would have been three to four hours of my time, spread across three separate mornings of interrupted work.&lt;/p&gt;

&lt;p&gt;The comparison to point-and-shoot prompting is stark. "Refactor the auth module" stops when Claude runs out of obvious things to do. "/goal Auth module refactored with no TypeScript errors and 90%+ test coverage" stops when the work is actually done. That distinction is what makes /goal a fundamentally different interface, not just a convenience wrapper.&lt;/p&gt;

&lt;h2&gt;
  
  
  Background Sessions: The Full Control Surface
&lt;/h2&gt;

&lt;p&gt;Background sessions are not new to Claude Code, but the 2.1.x releases added enough configuration surface that they now behave like first-class agent deployments rather than a niche CLI trick.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="c"&gt;# Start a simple background session&lt;/span&gt;
claude &lt;span class="nt"&gt;--bg&lt;/span&gt; &lt;span class="s2"&gt;"Audit the codebase for security issues in the auth module"&lt;/span&gt;

&lt;span class="c"&gt;# Fully configured background agent&lt;/span&gt;
claude &lt;span class="nt"&gt;--bg&lt;/span&gt; &lt;span class="nt"&gt;--name&lt;/span&gt; &lt;span class="s2"&gt;"security-audit"&lt;/span&gt;   &lt;span class="nt"&gt;--model&lt;/span&gt; claude-opus-4-7   &lt;span class="nt"&gt;--effort&lt;/span&gt; high   &lt;span class="nt"&gt;--permission-mode&lt;/span&gt; auto   &lt;span class="nt"&gt;--settings&lt;/span&gt; ./.claude/settings.json   &lt;span class="nt"&gt;--mcp-config&lt;/span&gt; ./.claude/mcp.json   &lt;span class="s2"&gt;"Complete the security review and output findings to SECURITY_REPORT.md"&lt;/span&gt;

&lt;span class="c"&gt;# Resume a background session interactively&lt;/span&gt;
/resume

&lt;span class="c"&gt;# Resume by specific session ID&lt;/span&gt;
claude &lt;span class="nt"&gt;--resume&lt;/span&gt; 
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;--fallback-model&lt;/code&gt; flag is worth knowing for production workflows. If the primary model hits a rate limit or quota boundary, Claude Code falls back to the specified alternative instead of failing hard:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;claude &lt;span class="nt"&gt;--bg&lt;/span&gt; &lt;span class="nt"&gt;--model&lt;/span&gt; claude-opus-4-7   &lt;span class="nt"&gt;--fallback-model&lt;/span&gt; claude-sonnet-4-6   &lt;span class="s2"&gt;"Refactor the payment processing module"&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;For repositories where git worktrees cause problems — monorepos with symlinks, certain CI-generated layouts, some Windows configurations — set &lt;code&gt;"worktree.bgIsolation": "none"&lt;/code&gt; in your settings.json. Background sessions will then edit the working copy directly instead of creating an isolated worktree. This unblocks a significant class of production use cases that were painful before 2.1.143.&lt;/p&gt;

&lt;p&gt;Empty idle background sessions auto-retire after five minutes. Sessions that finish their work but leave a background shell running move to "Completed" rather than "Running". These distinctions matter when you are managing six sessions and need to know which ones are still doing something versus which ones have finished and are just consuming memory.&lt;/p&gt;

&lt;h2&gt;
  
  
  New Agent Flags: Configure Everything
&lt;/h2&gt;

&lt;p&gt;The v2.1.142 release added a set of flags that turn what used to be informal defaults into explicit, preservable configuration. All of these work in both &lt;code&gt;claude&lt;/code&gt; and &lt;code&gt;claude agents&lt;/code&gt;:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;claude &lt;span class="nt"&gt;--add-dir&lt;/span&gt; ../shared-lib          &lt;span class="c"&gt;# Give Claude read access to a directory outside cwd&lt;/span&gt;
claude &lt;span class="nt"&gt;--settings&lt;/span&gt; ./.claude/prod.json  &lt;span class="c"&gt;# Use project-specific settings file&lt;/span&gt;
claude &lt;span class="nt"&gt;--mcp-config&lt;/span&gt; ./.claude/mcp.json &lt;span class="c"&gt;# Attach specific MCP servers to this session&lt;/span&gt;
claude &lt;span class="nt"&gt;--plugin-dir&lt;/span&gt; ./.claude/plugins  &lt;span class="c"&gt;# Load project-specific plugins&lt;/span&gt;
claude &lt;span class="nt"&gt;--permission-mode&lt;/span&gt; auto           &lt;span class="c"&gt;# No prompts for safe file operations&lt;/span&gt;
claude &lt;span class="nt"&gt;--effort&lt;/span&gt; xhigh                   &lt;span class="c"&gt;# Maximum reasoning depth for trust-boundary tasks&lt;/span&gt;
claude &lt;span class="nt"&gt;--dangerously-skip-permissions&lt;/span&gt;  &lt;span class="c"&gt;# Full bypass (use only in sandboxed environments)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;--add-dir&lt;/code&gt; flag solves a recurring pain point. Claude Code previously could not read files outside the current working directory without you changing directories first. With &lt;code&gt;--add-dir&lt;/code&gt;, you can give an agent access to a shared library, a design system package, or a documentation directory outside the project root — without restructuring your project layout to accommodate it.&lt;/p&gt;

&lt;p&gt;For multi-agent orchestration, these flags let you configure each dispatched subagent independently. A lead orchestrator running at &lt;code&gt;--effort high&lt;/code&gt; can dispatch subagents with lower effort for mechanical tasks like formatting or renaming, controlling cost across the entire system. For patterns on structuring these systems, the &lt;a href="https://dev.to/blogs/claude-code-multi-agent-coordination-agent-teams-guide-2026"&gt;multi-agent coordination guide&lt;/a&gt; covers orchestrator-worker architectures in detail.&lt;/p&gt;

&lt;h2&gt;
  
  
  Three Workflows That Changed How I Work
&lt;/h2&gt;

&lt;h3&gt;
  
  
  1. The Background Audit
&lt;/h3&gt;

&lt;p&gt;Every Friday, I run a background audit against the week's merged PRs. The agent reads the diff, checks for patterns from our CLAUDE.md security rules, and writes findings to a WEEKLY_AUDIT.md file. I come back Monday to a report rather than a vague sense that I should probably review something.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;claude &lt;span class="nt"&gt;--bg&lt;/span&gt; &lt;span class="nt"&gt;--name&lt;/span&gt; &lt;span class="s2"&gt;"weekly-audit"&lt;/span&gt;   &lt;span class="nt"&gt;--model&lt;/span&gt; claude-opus-4-7   &lt;span class="nt"&gt;--effort&lt;/span&gt; high   &lt;span class="nt"&gt;--permission-mode&lt;/span&gt; auto   &lt;span class="s2"&gt;"Read all changes merged this week. Cross-reference against .claude/rules/trust-boundary.md. Write WEEKLY_AUDIT.md with findings ranked by severity. Flag any payment or auth path changes explicitly."&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  2. The Completion Gate
&lt;/h3&gt;

&lt;p&gt;Before any PR goes out, I set a /goal with the exact criteria from our definition of done. Not a checklist I run through manually. Not a reminder to check TypeScript. A condition Claude satisfies or keeps working:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;/goal All TypeScript type errors resolved. All unit tests pass. No console.log statements remaining. ESLint reports zero errors on changed files.
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Claude works through the list systematically. It does not stop until every condition is true. This replaced my pre-PR checklist habit, which I was reliably skipping under deadline pressure.&lt;/p&gt;

&lt;h3&gt;
  
  
  3. The Pinned Session
&lt;/h3&gt;

&lt;p&gt;I keep one pinned session open in Agent View for the project I am actively shipping. It holds project context, MCP server connections, and permission settings — configured once, preserved across updates. When I need Claude for something quick, I jump into the pinned session instead of starting a cold context window. Auto-restart on updates means I get new Claude Code features without losing the session configuration.&lt;/p&gt;

&lt;h2&gt;
  
  
  The /usage Command: Real Cost Visibility
&lt;/h2&gt;

&lt;p&gt;Starting in v2.1.149, &lt;code&gt;/usage&lt;/code&gt; breaks down your token costs by category: skills, subagents, plugins, and MCP server calls. Before this update, the aggregate cost was visible but opaque — you could not tell whether a session's cost was driven by MCP tool calls, recursive subagent spawning, or the main conversation. That distinction matters when you are optimizing a multi-agent workflow for cost efficiency.&lt;/p&gt;

&lt;p&gt;For MCP-heavy workflows, the &lt;a href="https://dev.to/blogs/mcp-servers-explained-how-claude-code-connects-to-everything"&gt;MCP servers guide&lt;/a&gt; covers patterns for keeping call counts reasonable. An agent that calls an MCP server 50 times in a session is often doing something that could be batched into 3–5 calls with better tool design. /usage makes that pattern visible instead of hiding it inside an aggregate number.&lt;/p&gt;

&lt;h2&gt;
  
  
  What to Do Right Now
&lt;/h2&gt;

&lt;p&gt;Update to v2.1.149 or later: &lt;code&gt;npm update -g @anthropic-ai/claude-code&lt;/code&gt;. Then run &lt;code&gt;claude agents&lt;/code&gt; and look at what is actually running. Most developers are surprised to find sessions they backgrounded and forgot. Pin the ones that matter with Ctrl+T so they survive the next update cycle.&lt;/p&gt;

&lt;p&gt;For any task that takes more than 20 minutes to specify, set a &lt;code&gt;/goal&lt;/code&gt; with the completion criteria instead of a task description. The difference in outcome is consistent enough that I now default to /goal for anything beyond a single-file edit.&lt;/p&gt;

&lt;p&gt;If you are building production workflows with background agents, read the new flag documentation before committing to an architecture. The &lt;code&gt;--permission-mode&lt;/code&gt;, &lt;code&gt;--fallback-model&lt;/code&gt;, and &lt;code&gt;--add-dir&lt;/code&gt; flags together create a configuration surface that was not possible before May 2026. The agents you can build now are meaningfully more reliable than what shipped in April.&lt;/p&gt;

&lt;h2&gt;
  
  
  The CLAUDE.md templates, agent skill starters, and MCP server boilerplates for building these workflows are available at &lt;a href="https://dev.to/"&gt;wowhow.cloud&lt;/a&gt; — pay once, configure once, ship reliably.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/claude-code-21-agent-view-goal-command-autonomous-developer-guide-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>claudecode</category>
      <category>autonomouscoding</category>
    </item>
    <item>
      <title>Claude for Small Business: 15 Workflows &amp; Setup Guide 2026</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Fri, 22 May 2026 12:22:36 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/claude-for-small-business-15-workflows-setup-guide-2026-4kak</link>
      <guid>https://forem.com/akaranjkar08/claude-for-small-business-15-workflows-setup-guide-2026-4kak</guid>
      <description>&lt;p&gt;&lt;strong&gt;Anthropic launched Claude for Small Business on May 13, 2026 — and it is the most practical deployment of AI in daily business operations to date. Rather than a chatbot you open in a separate tab, this package embeds 15 ready-to-run agentic workflows directly into the tools small businesses already pay for: QuickBooks, PayPal, HubSpot, Canva, DocuSign, Google Workspace, Microsoft 365, and Slack. Here is everything you need to know to evaluate, set up, and get real value from it.&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;The core design principle is deceptively simple: Claude does the work, then asks your approval before anything sends, posts, or pays. If your QuickBooks user cannot see a vendor's banking details today, they cannot see those details through Claude either. The permission model is exactly what every business owner feared they would have to configure themselves — and Anthropic built it in from day one.&lt;/p&gt;

&lt;h2&gt;
  
  
  What Is Claude for Small Business?
&lt;/h2&gt;

&lt;p&gt;Claude for Small Business is a package built on top of Claude Cowork — Anthropic's collaborative workspace layer — that ships with three things: 15 ready-to-run agentic workflows, 15 reusable skills, and connectors to eight business tools. Each workflow is an end-to-end job, not a one-shot prompt. You authorize it once, Claude reads the relevant data, runs the analysis or drafting, and presents the output for your review before anything leaves the system.&lt;/p&gt;

&lt;p&gt;The eight connected tools at launch are QuickBooks, PayPal, HubSpot, Canva, DocuSign, Google Workspace, Microsoft 365, and Slack. These cover the core operational surface of most small businesses: accounting, payments, CRM, design, contracts, email and calendar, productivity, and internal communication.&lt;/p&gt;

&lt;p&gt;Pricing is straightforward. It is included with any existing Claude Pro ($20/month), Claude Max ($100–$200/month), or Claude Team subscription at no additional charge. You only pay for the partner tools you already use. Setup requires no IT support and takes under 30 minutes.&lt;/p&gt;

&lt;h2&gt;
  
  
  The 15 Workflows: What They Actually Do
&lt;/h2&gt;

&lt;p&gt;The workflows span six categories: finance, operations, sales, marketing, HR, and customer service. Rather than listing all fifteen mechanically, here are the five that address the highest-friction recurring tasks for most small businesses.&lt;/p&gt;

&lt;h3&gt;
  
  
  1. Cash Flow Reconciliation and Forecasting
&lt;/h3&gt;

&lt;p&gt;Claude checks your QuickBooks cash position against incoming PayPal settlements, builds a 30-day forward forecast, ranks overdue invoices by amount and age, and queues payment reminder drafts for your review. What previously took a bookkeeper two hours on Monday morning takes Claude under three minutes. Every draft sits in your queue until you approve it — nothing sends automatically. For a founder doing their own bookkeeping, this single workflow alone justifies the subscription.&lt;/p&gt;

&lt;h3&gt;
  
  
  2. Month-End Close Packet
&lt;/h3&gt;

&lt;p&gt;Claude reconciles your books against bank and payment settlements, flags every mismatch with a plain-English explanation, writes a P&amp;amp;L summary your accountant can read without translation, and exports a close packet formatted for PDF delivery. The workflow eliminates the manual copy-and-reconcile cycle that makes month-end painful for small teams running lean financial operations.&lt;/p&gt;

&lt;h3&gt;
  
  
  3. Sales Campaign Builder
&lt;/h3&gt;

&lt;p&gt;Claude identifies slow revenue periods in your HubSpot data, analyzes the performance of past campaigns, drafts a promotional strategy, and generates campaign assets in Canva — all before anything goes live. You review the strategy, the copy, and the design in one place. If you want to change the offer or the headline, you instruct Claude and it regenerates. The complete cycle from "we need a campaign" to "here are the assets for your review" is a single workflow invocation.&lt;/p&gt;

&lt;h3&gt;
  
  
  4. Contract Generation and Signature Routing
&lt;/h3&gt;

&lt;p&gt;Claude drafts standard agreements using templates you have previously approved, generates the DocuSign envelope, and routes it to the correct counterparty. The workflow pulls contact information from HubSpot, so you are not manually copying email addresses between apps. You review the contract before it leaves your system. Signature reminders run on the schedule you configure, not by Claude autonomously deciding when to follow up.&lt;/p&gt;

&lt;h3&gt;
  
  
  5. Hiring and Onboarding Coordination
&lt;/h3&gt;

&lt;p&gt;The HR workflow drafts job descriptions, schedules interviews through Google Calendar, generates offer letters based on your standard terms, sends DocuSign envelopes for new hire paperwork, and queues the onboarding checklist in Slack. A process that typically spans three tools and multiple copy-paste operations becomes a single workflow that presents every document for your approval at each step.&lt;/p&gt;

&lt;h2&gt;
  
  
  Skills vs. Workflows: The Distinction That Matters
&lt;/h2&gt;

&lt;p&gt;The 15 skills are different from the 15 workflows. Workflows are end-to-end operations — they connect multiple tools, run analysis, and produce a complete output. Skills are reusable building blocks: specific ways Claude knows how to handle a particular type of task that you can invoke in conversation or chain into custom workflows you design yourself.&lt;/p&gt;

&lt;p&gt;Examples of skills include: drafting a professional email to a delinquent client, formatting a financial report for a specific audience, generating a social post from a blog excerpt, or summarizing a PDF contract into plain English. These are not full workflows, but they are the components that make custom workflows fast to build as you understand the system more deeply.&lt;/p&gt;

&lt;p&gt;Start with the pre-built workflows for immediate ROI. Then, as you identify recurring tasks that do not fit a pre-built workflow, chain skills together to create your own. This is where the system becomes significantly more powerful than any individual AI app you have used before.&lt;/p&gt;

&lt;h2&gt;
  
  
  The Permission Architecture: How Trust Actually Works
&lt;/h2&gt;

&lt;p&gt;The most important thing to understand about Claude for Small Business is not what it can do — it is how it handles what it should not do.&lt;/p&gt;

&lt;p&gt;Every connector respects the permissions that exist in the underlying tool. If an employee has read-only access to QuickBooks, Claude has read-only access to QuickBooks when that employee is using it. If a team member cannot approve payments in PayPal, Claude cannot approve payments on their behalf. This is not a Claude-level guardrail layered on top — it is native permission inheritance from each connected application, enforced at the OAuth token level.&lt;/p&gt;

&lt;p&gt;The human-in-the-loop requirement for any external action is built into every workflow. Claude drafts the invoice reminder; you approve and send. Claude builds the campaign assets; you approve and publish. Claude prepares the contract; you review and route. This is the correct architecture for a business tool: AI as a tireless, accurate preparer, with the human retaining every consequential decision.&lt;/p&gt;

&lt;p&gt;This design choice distinguishes Claude for Small Business from the "AI agent deleted our data" incidents that made headlines in early 2026. Anthropic made a deliberate product decision to build agentic capability without autonomous execution on financial or legal actions. For a small business with real money, real clients, and real legal exposure, that constraint is the right one.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pricing Reality Check
&lt;/h2&gt;

&lt;p&gt;The effective cost depends on where you sit in the Claude subscription stack. Claude Pro at $20/month is a personal tier; team features require Claude Team, billed per seat. Claude Max at $100–$200/month includes Claude for Small Business at no additional charge and is the cleanest entry point for a solo founder who wants all 15 workflows immediately.&lt;/p&gt;

&lt;p&gt;The honest comparison is against the workflow time this replaces. Monthly bookkeeping review with a QuickBooks ProAdvisor runs $200–$500/month for a small operation. A part-time marketing assistant for campaign creation might cost $500–$1,500/month. A contract management platform beyond DocuSign's base tier adds $50–$200/month. Claude for Small Business does not replace any of these entirely, but it materially reduces the hours at each layer — which for a founder doing everything simultaneously, is the real ROI calculation.&lt;/p&gt;

&lt;p&gt;Anthropic is running a 10-city US tour through summer 2026, starting in Chicago, with free half-day workshops and a free month of Claude Max for every attendee. If you are evaluating the platform seriously and are in the US, attending before committing is worth the half day.&lt;/p&gt;

&lt;h2&gt;
  
  
  Limitations Worth Knowing Before You Commit
&lt;/h2&gt;

&lt;p&gt;Claude for Small Business launched US-focused in May 2026. International connector support — particularly for non-US accounting software like Xero, MYOB, or Tally — is not available at launch. If your financial stack is outside the eight supported tools, the finance workflows are unavailable until Anthropic expands the connector library.&lt;/p&gt;

&lt;p&gt;The 15 pre-built workflows cover common patterns well, but they are not infinitely configurable out of the box. If your business has unusual contract structures, multi-entity accounting, or complex approval chains, you will need to work with skills rather than pre-built workflows — which requires more setup time and a deeper understanding of how Claude handles context across multi-step operations.&lt;/p&gt;

&lt;p&gt;The system requires that you connect real accounts with real data. There is no sandbox mode for evaluation before authorization. If privacy or data security are concerns — particularly for businesses in regulated industries such as healthcare or legal services — read Anthropic's data handling terms carefully before connecting QuickBooks or DocuSign credentials. The same diligence applies to any third-party AI platform with access to financial data.&lt;/p&gt;

&lt;h2&gt;
  
  
  Who Should Start With Claude for Small Business
&lt;/h2&gt;

&lt;p&gt;The clearest immediate candidates are founders running businesses between $500k and $5M in annual revenue with a small team: typically one to fifteen people. At this scale, the founder is often doing bookkeeping review, approving contracts, drafting campaigns, and managing hiring simultaneously — exactly the operational workload the 15 workflows address directly.&lt;/p&gt;

&lt;p&gt;Service businesses — agencies, consultancies, professional services firms — will see the fastest payback from the contract and invoicing workflows. Product businesses with e-commerce components will see the most value from the QuickBooks + PayPal reconciliation and the HubSpot + Canva campaign builder.&lt;/p&gt;

&lt;p&gt;Teams already running on Google Workspace or Microsoft 365 get the deepest integration since both are supported connectors from day one. Calendar scheduling, email drafting, and document generation all tie into the workflow layer without additional configuration.&lt;/p&gt;

&lt;h2&gt;
  
  
  Getting Started: Four Steps
&lt;/h2&gt;

&lt;p&gt;Setup requires no IT support and takes under 30 minutes. Log into Claude.ai and navigate to the Cowork section. The Small Business package surfaces under Marketplace or Integrations depending on your account tier.&lt;/p&gt;

&lt;p&gt;Connect QuickBooks first. The finance workflows deliver the highest ROI and the reconciliation workflow will produce a concrete output on real data within five minutes of connection — giving you an immediate proof point before you authorize any additional tool. Authorize the OAuth connection, confirm read/write permissions, and run the cash flow reconciliation workflow on your current data.&lt;/p&gt;

&lt;p&gt;Connect HubSpot next if you run an active CRM. The sales and marketing workflows are the second-fastest value delivery. Then connect the remaining tools in order of daily use priority. Each connection is a separate OAuth authorization; you are not granting Claude blanket access to your entire business stack at once.&lt;/p&gt;

&lt;h2&gt;
  
  
  Claude for Small Business represents a meaningful shift in how small businesses can use AI — not as a chat assistant, but as a workflow layer embedded in the tools that run the business. The human-in-the-loop architecture, native permission inheritance, and pre-built workflow library solve the three main blockers that kept most small businesses from deploying AI in operational roles: trust, access control, and setup complexity. Whether the full 15-workflow suite fits your specific business will become clear in the first week of use.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/claude-for-small-business-complete-guide-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>claudefor</category>
      <category>anthropicsmall</category>
      <category>claudecowork</category>
      <category>aifor</category>
    </item>
    <item>
      <title>OpenAI Files for IPO: What Every Developer Building on OpenAI Needs to Know (2026)</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Fri, 22 May 2026 06:23:34 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/openai-files-for-ipo-what-every-developer-building-on-openai-needs-to-know-2026-2iom</link>
      <guid>https://forem.com/akaranjkar08/openai-files-for-ipo-what-every-developer-building-on-openai-needs-to-know-2026-2iom</guid>
      <description>&lt;p&gt;&lt;strong&gt;OpenAI filed its IPO prospectus confidentially this week, targeting a September 2026 public listing at a valuation above $1 trillion — and every developer building production applications on the OpenAI API needs to understand what that means for their business. IPOs do not just create paper wealth for insiders; they fundamentally reshape how companies operate. Pricing decisions, model release cadence, research openness, and API reliability all shift when public market accountability enters the picture. This guide breaks down OpenAI's financial position, what the Microsoft partnership restructure actually changes, and the concrete steps developers should take before the S-1 becomes public.&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;The filing is happening in the middle of the most competitive moment in AI history. Anthropic is targeting an October 2026 IPO. SpaceX filed its own S-1 on May 20. Both companies share overlapping infrastructure deals, investors, and developer mindshare. The AI infrastructure layer — APIs that millions of developers depend on — is about to become part of the public markets conversation in a way it never has been before. The implications are not theoretical.&lt;/p&gt;

&lt;h2&gt;
  
  
  What We Know About OpenAI's Financials
&lt;/h2&gt;

&lt;p&gt;OpenAI's March 2026 funding round disclosed approximately $2 billion in monthly revenue — roughly $25 billion annualized, up from $20 billion at the close of 2025. The company closed a $122 billion funding round in late March 2026 at an $852 billion post-money valuation, making it one of the largest private financings in technology history. Those are staggering numbers, but they come with important context that the public S-1 will either confirm or complicate.&lt;/p&gt;

&lt;p&gt;What investors and developers still cannot see — until the public S-1 drops — is gross margin after compute costs. Large language model inference is extraordinarily capital-intensive. Training and serving frontier models like GPT-5.5 requires GPU clusters at a scale that makes compute cost one of the largest variables in the economics. A company earning $25 billion in revenue but spending $22 billion on compute, salaries, and infrastructure has a very different financial profile than the headline revenue number suggests.&lt;/p&gt;

&lt;p&gt;CFO Sarah Friar's blog post in January 2026 confirmed that the company crossed $20 billion annualized. What she did not disclose was burn rate, capex obligations, or the gross margin after infrastructure costs. Public market investors will demand those numbers. If compute economics are tighter than the valuation assumes, the pressure to raise API prices or cut model availability will intensify after the IPO.&lt;/p&gt;

&lt;p&gt;For developers, watch the S-1 filing for three specific disclosures. First, gross margin — anything below 50% signals sustained price pressure. Second, API revenue as a percentage of total revenue — if enterprise subscriptions (ChatGPT Enterprise, OpenAI for Business) are growing faster than API revenue, that signals a de-prioritization of the developer tier. Third, capex guidance — if the company is committing to $30+ billion in infrastructure spend annually, the capital needs will put pressure on monetization timelines.&lt;/p&gt;

&lt;h2&gt;
  
  
  The Microsoft Restructure: What Actually Changed for Developers
&lt;/h2&gt;

&lt;p&gt;The most underreported aspect of OpenAI's IPO preparation is the renegotiated Microsoft partnership finalized in May 2026. Under the new terms, OpenAI's total revenue-share payments to Microsoft are capped at $38 billion through 2030 — down from a projected $135 billion under the prior agreement. That $97 billion difference is structural improvement in OpenAI's cash flow position that directly affects how much financial pressure the company faces to aggressively monetize the API.&lt;/p&gt;

&lt;p&gt;Microsoft retains approximately 27% of OpenAI on a diluted basis, valued at roughly $135 billion at the $852 billion round valuation. As the company moves toward an IPO, Microsoft's role shifts from a capital provider to a major shareholder with public market exposure. That alignment of interests changes the dynamic: Microsoft now has an incentive for OpenAI's public valuation to hold, which creates pressure to demonstrate stable, growing API revenue rather than subsidizing below-market pricing.&lt;/p&gt;

&lt;p&gt;For developers building on Azure OpenAI Service, the restructure matters directly. Azure OpenAI pricing and model availability has historically tracked the direct API — but as the commercial interests of both companies sharpen around the IPO window, divergence is possible. A developer team with major Azure commitments may find its OpenAI model access governed through a different SLA and cadence than a team using the direct API. Mapping your specific integration path now, before the IPO paperwork locks in new commercial frameworks, is worth doing proactively.&lt;/p&gt;

&lt;h2&gt;
  
  
  API Pricing Under Public Market Pressure
&lt;/h2&gt;

&lt;p&gt;The core developer concern with any AI company IPO is straightforward: does going public accelerate price increases? The honest answer is that it depends on where the company sits in its growth phase — and OpenAI's trajectory suggests measured caution is warranted.&lt;/p&gt;

&lt;p&gt;OpenAI has historically used aggressive pricing as a growth lever. GPT-4o remains available on the free tier. GPT-5.5 dropped to $2/$8 per million tokens within weeks of launch. The company has subsidized developer adoption with below-cost pricing while scaling user growth. That strategy is sustainable with private capital and venture backing. It becomes structurally harder to justify on a quarterly earnings call when public investors are watching gross margin compress against capex commitments.&lt;/p&gt;

&lt;p&gt;The historical precedent from SaaS infrastructure companies that went public is instructive. Twilio raised prices twice in the 18 months following its 2016 IPO. Snowflake restructured its pricing from on-demand to committed-use contracts to smooth revenue recognition for Wall Street analysts. Stripe's private pricing flexibility narrowed significantly as the company grew closer to IPO readiness. These are not failures — they are the predictable consequence of public market accountability requirements.&lt;/p&gt;

&lt;p&gt;What this means in practice for OpenAI: the most likely scenario is not sudden price spikes but gradual reduction in free-tier generosity, more aggressive promotion of committed-use enterprise contracts, and slower pass-through of model cost reductions to API pricing. The era of GPT-4-class models becoming free-tier access almost certainly ends within 12 months of the IPO. Developers should baseline their current costs now and build cost-increase scenarios into runway models before the S-1 drops.&lt;/p&gt;

&lt;h2&gt;
  
  
  Model Release Cadence and Research Openness
&lt;/h2&gt;

&lt;p&gt;Public companies in AI face a contradictory pressure: investors want predictable recurring revenue, but AI capability advances on an inherently unpredictable research timeline. OpenAI's current strategy of releasing models when they are ready — GPT-5.5 released May 2026, GPT-5.5 Instant for ChatGPT in the same month — gives the company maximum technical flexibility but creates inconsistent revenue recognition that equity analysts will push back on.&lt;/p&gt;

&lt;p&gt;Post-IPO, expect more structured release cadences aligned with the quarterly earnings calendar. Research releases that previously happened when ready will increasingly align with quarterly announcements. This is not necessarily bad for developers — predictability in model updates makes API versioning and migration planning considerably easier — but it reduces the sense that you are always accessing the frontier model as fast as research progress allows.&lt;/p&gt;

&lt;p&gt;Research openness is the more significant long-term concern. OpenAI's name grows increasingly ironic — the company has not open-sourced a frontier model in several years. The commercial pressures of being a public company make sharing model weights even less likely. If competitive advantage lives in the model, and the model is the primary revenue-generating asset, the incentive to open-source any meaningful component of that asset disappears entirely under public market scrutiny. Developers building on OpenAI should assume that access to model internals, fine-tuning endpoints on frontier models, and research previews will become more restricted rather than more open over the next 18 months.&lt;/p&gt;

&lt;h2&gt;
  
  
  Building a Multi-Provider Strategy Before the IPO
&lt;/h2&gt;

&lt;p&gt;The most actionable response to OpenAI's IPO is to reduce API-level lock-in now, while switching costs are still manageable. Teams that built exclusively on the OpenAI API have accumulated technical debt in the form of provider-specific features: OpenAI function calling syntax, OpenAI Assistants API patterns, OpenAI file handling and thread management. Migrating those to provider-agnostic interfaces after a price increase happens under pressure — the worst possible conditions for careful engineering.&lt;/p&gt;

&lt;p&gt;The multi-provider pattern that has emerged as the production standard in 2026 uses a routing layer — LiteLLM, OpenRouter, or a custom abstraction — that normalizes the OpenAI-compatible API interface across multiple providers. Anthropic's Claude, Google's Gemini, and OpenAI's GPT all accept requests in compatible formats when routed through these layers. The incremental engineering cost is a few hours; the optionality created is substantial.&lt;/p&gt;

&lt;p&gt;A minimal provider hedge for a production application looks like this: route non-latency-sensitive tasks — batch summarization, classification, document extraction — to whichever provider currently offers the best cost-per-quality ratio. Route latency-sensitive tasks such as real-time chat and code completion to your primary provider. Keep model-specific integrations in an adapter layer that can be swapped without touching business logic. Evaluate at least one alternative provider monthly to maintain institutional familiarity and keep your routing configuration current.&lt;/p&gt;

&lt;p&gt;The goal is not to abandon OpenAI. GPT-5.5 and its successors will likely remain among the strongest models for many use cases throughout the IPO period and beyond. The goal is to ensure that a price increase or API policy change is a decision you make deliberately, from a position of optionality, rather than a crisis you react to from a position of lock-in.&lt;/p&gt;

&lt;h2&gt;
  
  
  The Competitive Landscape After Three Public AI Companies
&lt;/h2&gt;

&lt;p&gt;OpenAI's IPO does not happen in isolation. Anthropic is targeting an October 2026 public listing. Google's Gemini business is already public through Alphabet, with AI revenue now broken out separately in quarterly reports. The era of private AI companies competing on research timelines without public accountability is ending for all three major API providers simultaneously.&lt;/p&gt;

&lt;p&gt;This convergence creates a meaningful developer opportunity: all three companies will be competing for developer mindshare under public market scrutiny, which historically increases investment in developer tools, documentation, pricing competitiveness, and ecosystem programs. The 18-24 months following the OpenAI IPO are likely to be the most actively competitive period for API pricing and developer tooling in AI history. Each company will be demonstrating developer ecosystem health to public market investors and analysts who can compare them directly.&lt;/p&gt;

&lt;p&gt;Developers who maintain active integrations with multiple providers are positioned to benefit from this dynamic. Being a credible alternative-ready customer gives leverage in enterprise contract discussions that a provider-locked developer simply does not have. When three public companies are competing for the same developer spend on the same earnings cycle, the developer with optionality is the one with pricing power.&lt;/p&gt;

&lt;h2&gt;
  
  
  Three Things Developers Should Do This Week
&lt;/h2&gt;

&lt;p&gt;The IPO filing is happening now. Here is what is worth doing before the public S-1 drops and the market narrative solidifies:&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Audit your OpenAI API spend by feature.&lt;/strong&gt; Break down your monthly spend by which specific capabilities you use: which models, which endpoints, which features have no direct equivalent elsewhere. Identify the 20% of your OpenAI usage that is genuinely irreplaceable versus the 80% that could be routed to an alternative today. The audit itself is valuable even if you never migrate a single workload — it gives you a clear picture of your actual exposure.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Set up a parallel environment with one alternative provider.&lt;/strong&gt; Register for Anthropic API access or Gemini API access if you have not already. Run a representative sample of your production workloads against the alternative. Measure quality, latency, and cost. This takes a few hours of engineering time and removes the knowledge gap that makes migration feel more daunting than it actually is.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Define your cost escalation thresholds now.&lt;/strong&gt; If your OpenAI costs increase by 25%, 50%, or 2x, what happens to your product economics and unit margins? Define those thresholds explicitly. Build a simple cost dashboard that surfaces provider spend on a daily basis. When the IPO-driven pricing pressure arrives — and historical precedent suggests it will — you will know immediately rather than discovering it in the next monthly invoice.&lt;/p&gt;

&lt;h2&gt;
  
  
  OpenAI going public is a genuine milestone for the AI industry — the company that sparked the modern large language model era will be accountable to public markets for the first time. For developers, the filing week is the right moment to stress-test your infrastructure dependency and build the optionality that keeps you in control of your own product economics, regardless of what any single provider decides to do with its pricing strategy in the quarters ahead.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/openai-ipo-s1-filing-developer-ecosystem-impact-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>openaiipo</category>
      <category>openaiapi</category>
      <category>openais1</category>
    </item>
    <item>
      <title>Zod Validation: Type-Safe APIs &amp; Forms in TypeScript (Complete Guide)</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Thu, 21 May 2026 18:00:14 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/zod-validation-type-safe-apis-forms-in-typescript-complete-guide-3gjj</link>
      <guid>https://forem.com/akaranjkar08/zod-validation-type-safe-apis-forms-in-typescript-complete-guide-3gjj</guid>
      <description>&lt;p&gt;&lt;strong&gt;TypeScript types disappear at runtime. Your carefully typed &lt;code&gt;User&lt;/code&gt; interface means nothing when the JSON from an external API, a form submission, or a database query arrives as &lt;code&gt;unknown&lt;/code&gt;. Zod bridges this gap: you define a schema once, validate data against it at runtime, and get a TypeScript type back for free. This guide covers every Zod pattern you will use — from basic schemas to API validation, form handling, and OpenAPI generation.&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;If you are building TypeScript APIs or form-heavy applications, browse &lt;a href="https://dev.to/tools/"&gt;WOWHOW Tools&lt;/a&gt; for starter kits and check out the &lt;a href="https://dev.to/browse"&gt;full catalog&lt;/a&gt; for Next.js and React templates with validation built in.&lt;/p&gt;

&lt;h2&gt;
  
  
  Why Zod Over Alternatives
&lt;/h2&gt;

&lt;p&gt;Zod infers TypeScript types from schemas (schema-first, not type-first). It has zero dependencies, works in Node.js and browsers, and its error messages are structured objects you can use to build user-facing form errors without any extra work. It also chains neatly with transforms — parse, validate, and reshape data in one step.&lt;/p&gt;

&lt;h2&gt;
  
  
  Core Schema Types
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;zod&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="c1"&gt;// primitives&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;name&lt;/span&gt;    &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;age&lt;/span&gt;     &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;active&lt;/span&gt;  &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;boolean&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;created&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;date&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;id&lt;/span&gt;      &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;bigint&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

&lt;span class="c1"&gt;// string constraints&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;email&lt;/span&gt;    &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;email&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;url&lt;/span&gt;      &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;url&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;uuid&lt;/span&gt;     &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;uuid&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;slug&lt;/span&gt;     &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;regex&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sr"&gt;/^&lt;/span&gt;&lt;span class="se"&gt;[&lt;/span&gt;&lt;span class="sr"&gt;a-z0-9-&lt;/span&gt;&lt;span class="se"&gt;]&lt;/span&gt;&lt;span class="sr"&gt;+$/&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Lowercase letters, numbers, hyphens only&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;password&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;8&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;128&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;bio&lt;/span&gt;      &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;500&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;optional&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

&lt;span class="c1"&gt;// number constraints&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;price&lt;/span&gt;    &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;positive&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;finite&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;rating&lt;/span&gt;   &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;int&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;5&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;quantity&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;int&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;nonnegative&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

&lt;span class="c1"&gt;// literals and enums&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;role&lt;/span&gt;     &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;enum&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;admin&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;editor&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;viewer&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;status&lt;/span&gt;   &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;literal&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;active&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;exact&lt;/span&gt;    &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;union&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;literal&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;pending&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;literal&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;shipped&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;literal&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;delivered&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)])&lt;/span&gt;

&lt;span class="c1"&gt;// infer types automatically&lt;/span&gt;
&lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;Role&lt;/span&gt;   &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;infer&lt;/span&gt;   &lt;span class="c1"&gt;// 'admin' | 'editor' | 'viewer'&lt;/span&gt;
&lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;Email&lt;/span&gt;  &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;infer&lt;/span&gt;  &lt;span class="c1"&gt;// string (with runtime guarantee)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Object Schemas
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;UserSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;         &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;uuid&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;email&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;      &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;email&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;toLowerCase&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;  &lt;span class="c1"&gt;// transform to lowercase&lt;/span&gt;
  &lt;span class="na"&gt;firstName&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;  &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;50&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;lastName&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;   &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;50&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;role&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;       &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;enum&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;admin&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;editor&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;viewer&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]).&lt;/span&gt;&lt;span class="k"&gt;default&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;viewer&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;age&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;        &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;int&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;13&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;120&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;optional&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;createdAt&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;  &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;datetime&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;  &lt;span class="c1"&gt;// ISO 8601 string&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;User&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;infer&lt;/span&gt;

&lt;span class="c1"&gt;// parse: throws ZodError on failure&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;user&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;UserSchema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;parse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;rawData&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;// safeParse: returns { success, data } or { success, error }&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;result&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;UserSchema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;safeParse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;rawData&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;!&lt;/span&gt;&lt;span class="nx"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;success&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;console&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;flatten&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;
  &lt;span class="c1"&gt;// { fieldErrors: { email: ['Invalid email'] }, formErrors: [] }&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Nested Objects and Arrays
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;AddressSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;street&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;  &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;city&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;    &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;state&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;   &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;length&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;zipCode&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;regex&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sr"&gt;/^d&lt;/span&gt;&lt;span class="se"&gt;{5}(&lt;/span&gt;&lt;span class="sr"&gt;-d&lt;/span&gt;&lt;span class="se"&gt;{4})?&lt;/span&gt;&lt;span class="sr"&gt;$/&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;country&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;length&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="k"&gt;default&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;US&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;OrderSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;          &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;uuid&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;customerId&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;  &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;uuid&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;items&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;       &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;array&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
      &lt;span class="na"&gt;productId&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;uuid&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
      &lt;span class="na"&gt;quantity&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;  &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;int&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;positive&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
      &lt;span class="na"&gt;unitPrice&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;positive&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
    &lt;span class="p"&gt;})&lt;/span&gt;
  &lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Order must have at least one item&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;shippingAddress&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;AddressSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="na"&gt;total&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;       &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;positive&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;status&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;      &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;enum&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;pending&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;confirmed&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;shipped&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;delivered&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;cancelled&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]),&lt;/span&gt;
  &lt;span class="na"&gt;notes&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;       &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1000&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;nullable&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="k"&gt;default&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;Order&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;infer&lt;/span&gt;

&lt;span class="c1"&gt;// tuple with mixed types&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;CoordSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;tuple&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;()])&lt;/span&gt;  &lt;span class="c1"&gt;// [lat, lng]&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;TripleSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;tuple&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;boolean&lt;/span&gt;&lt;span class="p"&gt;()])&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Transforms: Parse and Reshape in One Step
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// coerce strings from form inputs&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;FormPriceSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;transform&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;val&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;parseFloat&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;val&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;pipe&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;positive&lt;/span&gt;&lt;span class="p"&gt;())&lt;/span&gt;

&lt;span class="c1"&gt;// parse ISO date strings into Date objects&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;DateFromStringSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;datetime&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;transform&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;str&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Date&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;str&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;

&lt;span class="c1"&gt;// normalize phone numbers&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;PhoneSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;transform&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;val&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;val&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;replace&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sr"&gt;/&lt;/span&gt;&lt;span class="se"&gt;[^&lt;/span&gt;&lt;span class="sr"&gt;0-9&lt;/span&gt;&lt;span class="se"&gt;]&lt;/span&gt;&lt;span class="sr"&gt;/g&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;''&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;pipe&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;length&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Must be 10 digits&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;

&lt;span class="c1"&gt;// computed fields using transform&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;FullNameSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="na"&gt;firstName&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
    &lt;span class="na"&gt;lastName&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;  &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;transform&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="p"&gt;...&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;fullName&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{data.firstName} &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{data.lastName}`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;initials&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{data.firstName[0]}.&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{data.lastName[0]}.`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="p"&gt;}))&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;firstName&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;lastName&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;fullName&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;initials&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;FullNameSchema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;parse&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;firstName&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Anup&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="na"&gt;lastName&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;  &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Karanjkar&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;
&lt;span class="c1"&gt;// fullName: 'Anup Karanjkar', initials: 'A.K.'&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Refinements: Cross-Field and Async Validation
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// single-field refinement&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;PasswordSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;8&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;refine&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;val&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="sr"&gt;/&lt;/span&gt;&lt;span class="se"&gt;[&lt;/span&gt;&lt;span class="sr"&gt;A-Z&lt;/span&gt;&lt;span class="se"&gt;]&lt;/span&gt;&lt;span class="sr"&gt;/&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;test&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;val&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; &lt;span class="sr"&gt;/&lt;/span&gt;&lt;span class="se"&gt;[&lt;/span&gt;&lt;span class="sr"&gt;0-9&lt;/span&gt;&lt;span class="se"&gt;]&lt;/span&gt;&lt;span class="sr"&gt;/&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;test&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;val&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; &lt;span class="sr"&gt;/&lt;/span&gt;&lt;span class="se"&gt;[^&lt;/span&gt;&lt;span class="sr"&gt;a-zA-Z0-9&lt;/span&gt;&lt;span class="se"&gt;]&lt;/span&gt;&lt;span class="sr"&gt;/&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;test&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;val&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;message&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Password must contain uppercase, number, and special character&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;// cross-field refinement&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;PasswordConfirmSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="na"&gt;password&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;        &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;8&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
    &lt;span class="na"&gt;confirmPassword&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;refine&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;password&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;confirmPassword&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;message&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Passwords do not match&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;confirmPassword&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;   &lt;span class="c1"&gt;// attach error to specific field&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="c1"&gt;// date range validation&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;DateRangeSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="na"&gt;startDate&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;date&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
    &lt;span class="na"&gt;endDate&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;   &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;date&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;refine&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Date&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;endDate&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Date&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;startDate&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;message&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;End date must be after start date&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;endDate&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;// async refinement (e.g. database uniqueness check)&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;UniqueEmailSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;email&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;superRefine&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;email&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;ctx&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;exists&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;user&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;findUnique&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="na"&gt;where&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;email&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;
    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;exists&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="nx"&gt;ctx&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;addIssue&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
        &lt;span class="na"&gt;code&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;ZodIssueCode&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;custom&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;message&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Email already in use&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="p"&gt;})&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="c1"&gt;// use parseAsync for schemas with async refinements&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;validEmail&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;UniqueEmailSchema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;parseAsync&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;user@example.com&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  API Request Validation in Next.js Route Handlers
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;NextRequest&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;NextResponse&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;next/server&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;zod&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;CreateProductSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;        &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;3&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;100&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;price&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;       &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;positive&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;currency&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;    &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;enum&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;USD&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;INR&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;EUR&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]).&lt;/span&gt;&lt;span class="k"&gt;default&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;USD&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;5000&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;tags&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;        &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;array&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;()).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="k"&gt;default&lt;/span&gt;&lt;span class="p"&gt;([]),&lt;/span&gt;
  &lt;span class="na"&gt;published&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;   &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;boolean&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="k"&gt;default&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kc"&gt;false&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;CreateProductInput&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;infer&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;POST&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;NextRequest&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;let&lt;/span&gt; &lt;span class="nx"&gt;body&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;unknown&lt;/span&gt;
  &lt;span class="k"&gt;try&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;body&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;catch&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;NextResponse&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="na"&gt;error&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Invalid JSON&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;status&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;400&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;result&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;CreateProductSchema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;safeParse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;body&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;!&lt;/span&gt;&lt;span class="nx"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;success&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;NextResponse&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;error&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Validation failed&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;details&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;flatten&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nx"&gt;fieldErrors&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="p"&gt;},&lt;/span&gt;
      &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;status&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;422&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;product&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;createProduct&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;NextResponse&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;product&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;status&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;201&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// helper to validate any route handler input&lt;/span&gt;
&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;validateBody&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;schema&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;ZodType&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;NextRequest&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;let&lt;/span&gt; &lt;span class="na"&gt;body&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;unknown&lt;/span&gt;
    &lt;span class="k"&gt;try&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="nx"&gt;body&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;catch&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;NextResponse&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="na"&gt;error&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Invalid JSON&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;status&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;400&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;result&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;schema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;safeParse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;body&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;!&lt;/span&gt;&lt;span class="nx"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;success&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;NextResponse&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;error&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Validation failed&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;details&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;flatten&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nx"&gt;fieldErrors&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;status&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;422&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;data&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Form Validation with React Hook Form
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useForm&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;react-hook-form&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;zodResolver&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@hookform/resolvers/zod&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;zod&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;CheckoutSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;email&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;     &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;email&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Enter a valid email&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;firstName&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Required&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;50&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;lastName&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;  &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Required&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;50&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;address&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;   &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;5&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Enter full address&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;city&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;      &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Required&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;pinCode&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;   &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;regex&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sr"&gt;/^d&lt;/span&gt;&lt;span class="se"&gt;{6}&lt;/span&gt;&lt;span class="sr"&gt;$/&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Enter 6-digit PIN code&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;phone&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;     &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;regex&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sr"&gt;/^&lt;/span&gt;&lt;span class="se"&gt;[&lt;/span&gt;&lt;span class="sr"&gt;6-9&lt;/span&gt;&lt;span class="se"&gt;]&lt;/span&gt;&lt;span class="sr"&gt;d&lt;/span&gt;&lt;span class="se"&gt;{9}&lt;/span&gt;&lt;span class="sr"&gt;$/&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Enter valid Indian mobile number&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;CheckoutFormData&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;infer&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;CheckoutForm&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;register&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="nx"&gt;handleSubmit&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;formState&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;errors&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;isSubmitting&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useForm&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="na"&gt;resolver&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;zodResolver&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;CheckoutSchema&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;onSubmit&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;CheckoutFormData&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// data is fully typed AND validated&lt;/span&gt;
    &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;submitOrder&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;


      &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;errors&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;email&lt;/span&gt; &lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; 
&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;errors&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;email&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;message&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;


      &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;errors&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;pinCode&lt;/span&gt; &lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; 
&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;errors&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;pinCode&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;message&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;


        &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;isSubmitting&lt;/span&gt; &lt;span class="p"&gt;?&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Processing...&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt; &lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Place Order&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;


  &lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Schema Composition and Reuse
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// base schema — shared fields&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;TimestampedSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;createdAt&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;datetime&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;updatedAt&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;datetime&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;BaseEntitySchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;uuid&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
&lt;span class="p"&gt;}).&lt;/span&gt;&lt;span class="nf"&gt;merge&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;TimestampedSchema&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;// extend for specific entities&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;ProductSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;BaseEntitySchema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;extend&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;  &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;price&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;positive&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="c1"&gt;// pick/omit for partial schemas&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;ProductPreviewSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;ProductSchema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;pick&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;CreateProductInput&lt;/span&gt;   &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;ProductSchema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;omit&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;createdAt&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;updatedAt&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;UpdateProductInput&lt;/span&gt;   &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;CreateProductInput&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;partial&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;  &lt;span class="c1"&gt;// all fields optional&lt;/span&gt;

&lt;span class="c1"&gt;// discriminated unions&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;ApiResponseSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;discriminatedUnion&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;success&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
  &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="na"&gt;success&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;literal&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;  &lt;span class="na"&gt;data&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;unknown&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;}),&lt;/span&gt;
  &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="na"&gt;success&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;literal&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kc"&gt;false&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt; &lt;span class="na"&gt;error&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt; &lt;span class="na"&gt;code&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;}),&lt;/span&gt;
&lt;span class="p"&gt;])&lt;/span&gt;

&lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;ApiResponse&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;infer&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Environment Variable Validation
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// src/env.ts — validate at startup, not at request time&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;zod&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;EnvSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;NODE_ENV&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;        &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;enum&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;development&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;test&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;production&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]),&lt;/span&gt;
  &lt;span class="na"&gt;DATABASE_URL&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;    &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;url&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;REDIS_URL&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;       &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;url&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;optional&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;NEXTAUTH_SECRET&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;32&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;RAZORPAY_KEY_ID&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;startsWith&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;rzp_&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;PORT&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;            &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;coerce&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;int&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;positive&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="k"&gt;default&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;3000&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;parsed&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;EnvSchema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;safeParse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;process&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;env&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;!&lt;/span&gt;&lt;span class="nx"&gt;parsed&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;success&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;console&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Invalid environment variables:&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="nx"&gt;console&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;parsed&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;flatten&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nx"&gt;fieldErrors&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="nx"&gt;process&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;exit&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;env&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;parsed&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;
&lt;span class="c1"&gt;// env.PORT is typed as number, env.DATABASE_URL is typed as string&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  People Also Ask
&lt;/h2&gt;

&lt;h3&gt;
  
  
  What is the difference between &lt;code&gt;parse&lt;/code&gt; and &lt;code&gt;safeParse&lt;/code&gt; in Zod?
&lt;/h3&gt;

&lt;p&gt;&lt;code&gt;parse&lt;/code&gt; throws a &lt;code&gt;ZodError&lt;/code&gt; if validation fails. Use it when you want the error to propagate up as an exception — common in server-side code where you have a top-level error handler. &lt;code&gt;safeParse&lt;/code&gt; returns a discriminated union &lt;code&gt;{ success: true, data } | { success: false, error }&lt;/code&gt;. Use it when you need to handle validation failure gracefully without exceptions — typical for API request validation and form handling where you want to return structured error messages.&lt;/p&gt;

&lt;h3&gt;
  
  
  Can Zod schemas generate OpenAPI / JSON Schema documentation?
&lt;/h3&gt;

&lt;p&gt;Yes, via the &lt;code&gt;zod-to-json-schema&lt;/code&gt; package (&lt;code&gt;npm install zod-to-json-schema&lt;/code&gt;). Call &lt;code&gt;zodToJsonSchema(MySchema)&lt;/code&gt; to get a JSON Schema object you can plug into Swagger UI or any OpenAPI toolchain. For full OpenAPI 3.x spec generation, &lt;code&gt;@asteasolutions/zod-to-openapi&lt;/code&gt; provides a registry-based API that produces complete path definitions including request bodies, query params, and response schemas.&lt;/p&gt;

&lt;h3&gt;
  
  
  How do I handle validation errors in a way that maps to form field errors?
&lt;/h3&gt;

&lt;h2&gt;
  
  
  Use &lt;code&gt;error.flatten()&lt;/code&gt; on the &lt;code&gt;ZodError&lt;/code&gt;. It returns &lt;code&gt;{ fieldErrors: Record&amp;lt;string, string[]&amp;gt;, formErrors: string[] }&lt;/code&gt;. Field errors are keyed by the field path (e.g., &lt;code&gt;{ email: ['Invalid email address'] }&lt;/code&gt;). If you are using React Hook Form with &lt;code&gt;zodResolver&lt;/code&gt;, this mapping happens automatically — the resolver converts Zod errors into React Hook Form's error format and populates &lt;code&gt;formState.errors&lt;/code&gt; for you.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/zod-validation-typescript-api-forms-complete-guide-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>zodvalidation</category>
      <category>zodschema</category>
      <category>typescriptruntime</category>
      <category>zodform</category>
    </item>
    <item>
      <title>GitHub Actions CI/CD: Build a Complete Node.js Pipeline (2026)</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Thu, 21 May 2026 18:00:08 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/github-actions-cicd-build-a-complete-nodejs-pipeline-2026-150</link>
      <guid>https://forem.com/akaranjkar08/github-actions-cicd-build-a-complete-nodejs-pipeline-2026-150</guid>
      <description>&lt;p&gt;&lt;strong&gt;A CI/CD pipeline that catches bugs before deploy, builds reproducible Docker images, and ships to production with zero downtime is table stakes for any serious Node.js project. GitHub Actions makes all of this achievable with YAML configuration — but the defaults are slow, insecure, and fragile. This guide shows you every pattern you need, from caching to rollback.&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Looking for production-ready Node.js templates? Browse &lt;a href="https://dev.to/tools/"&gt;WOWHOW Tools&lt;/a&gt; and the &lt;a href="https://dev.to/browse"&gt;full product catalog&lt;/a&gt; for starter kits with CI/CD baked in.&lt;/p&gt;

&lt;h2&gt;
  
  
  Workflow Basics
&lt;/h2&gt;

&lt;p&gt;Every workflow lives in &lt;code&gt;.github/workflows/&lt;/code&gt;. The file name becomes the workflow name in the UI. Events trigger runs; jobs define what runs; steps are the individual commands.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# .github/workflows/ci.yml&lt;/span&gt;
&lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;CI&lt;/span&gt;

&lt;span class="na"&gt;on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;push&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;branches&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;main&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;develop&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
  &lt;span class="na"&gt;pull_request&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;branches&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;main&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

&lt;span class="c1"&gt;# cancel in-progress runs for the same branch&lt;/span&gt;
&lt;span class="na"&gt;concurrency&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;group&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ci-${{ github.ref }}&lt;/span&gt;
  &lt;span class="na"&gt;cancel-in-progress&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;test&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Test&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ubuntu-24.04&lt;/span&gt;
    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/checkout@v4&lt;/span&gt;

      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Setup Node&lt;/span&gt;
        &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/setup-node@v4&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;node-version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;22'&lt;/span&gt;
          &lt;span class="na"&gt;cache&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;npm'&lt;/span&gt;

      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm ci&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm run lint&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm test -- --coverage&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Matrix Builds: Test Across Node Versions
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;test-matrix&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Test Node ${{ matrix.node }} / ${{ matrix.os }}&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ matrix.os }}&lt;/span&gt;
    &lt;span class="na"&gt;strategy&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;fail-fast&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;matrix&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;node&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;20'&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;22'&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
        &lt;span class="na"&gt;os&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;ubuntu-24.04&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;windows-latest&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
        &lt;span class="na"&gt;exclude&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="c1"&gt;# skip windows + node 20 combination&lt;/span&gt;
          &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;os&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;windows-latest&lt;/span&gt;
            &lt;span class="na"&gt;node&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;20'&lt;/span&gt;

    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/checkout@v4&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/setup-node@v4&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;node-version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ matrix.node }}&lt;/span&gt;
          &lt;span class="na"&gt;cache&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;npm'&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm ci&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm test&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Caching for Speed
&lt;/h2&gt;

&lt;p&gt;Without caching, &lt;code&gt;npm ci&lt;/code&gt; downloads everything from npm on every run. With caching, subsequent runs skip the download entirely — cutting minutes off your pipeline.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/checkout@v4&lt;/span&gt;

  &lt;span class="c1"&gt;# node setup with built-in npm cache&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/setup-node@v4&lt;/span&gt;
    &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;node-version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;22'&lt;/span&gt;
      &lt;span class="na"&gt;cache&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;npm'&lt;/span&gt;             &lt;span class="c1"&gt;# hashes package-lock.json automatically&lt;/span&gt;

  &lt;span class="c1"&gt;# manual cache for build artifacts (e.g. Next.js .next/cache)&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Cache build artifacts&lt;/span&gt;
    &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/cache@v4&lt;/span&gt;
    &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;.next/cache&lt;/span&gt;
      &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;nextjs-${{ runner.os }}-${{ hashFiles('**/package-lock.json') }}-${{ hashFiles('**/*.ts', '**/*.tsx') }}&lt;/span&gt;
      &lt;span class="na"&gt;restore-keys&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
        &lt;span class="s"&gt;nextjs-${{ runner.os }}-${{ hashFiles('**/package-lock.json') }}-&lt;/span&gt;
        &lt;span class="s"&gt;nextjs-${{ runner.os }}-&lt;/span&gt;

  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm ci&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm run build&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Docker Build and Push
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;build-push&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Build &amp;amp; Push Docker Image&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ubuntu-24.04&lt;/span&gt;
    &lt;span class="na"&gt;permissions&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;contents&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;read&lt;/span&gt;
      &lt;span class="na"&gt;packages&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;write&lt;/span&gt;        &lt;span class="c1"&gt;# for GitHub Container Registry&lt;/span&gt;

    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/checkout@v4&lt;/span&gt;

      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Set up Docker Buildx&lt;/span&gt;
        &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;docker/setup-buildx-action@v3&lt;/span&gt;

      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Login to GHCR&lt;/span&gt;
        &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;docker/login-action@v3&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;registry&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ghcr.io&lt;/span&gt;
          &lt;span class="na"&gt;username&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ github.actor }}&lt;/span&gt;
          &lt;span class="na"&gt;password&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.GITHUB_TOKEN }}&lt;/span&gt;

      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Extract metadata&lt;/span&gt;
        &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;meta&lt;/span&gt;
        &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;docker/metadata-action@v5&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;images&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ghcr.io/${{ github.repository }}&lt;/span&gt;
          &lt;span class="na"&gt;tags&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
            &lt;span class="s"&gt;type=sha,prefix=sha-&lt;/span&gt;
            &lt;span class="s"&gt;type=ref,event=branch&lt;/span&gt;
            &lt;span class="s"&gt;type=semver,pattern={{version}}&lt;/span&gt;

      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Build and push&lt;/span&gt;
        &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;docker/build-push-action@v6&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;context&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;.&lt;/span&gt;
          &lt;span class="na"&gt;push&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ github.event_name != 'pull_request' }}&lt;/span&gt;
          &lt;span class="na"&gt;tags&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ steps.meta.outputs.tags }}&lt;/span&gt;
          &lt;span class="na"&gt;labels&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ steps.meta.outputs.labels }}&lt;/span&gt;
          &lt;span class="na"&gt;cache-from&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;type=gha&lt;/span&gt;        &lt;span class="c1"&gt;# GitHub Actions cache for layers&lt;/span&gt;
          &lt;span class="na"&gt;cache-to&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;type=gha,mode=max&lt;/span&gt;
          &lt;span class="na"&gt;build-args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
            &lt;span class="s"&gt;BUILD_DATE=${{ github.event.head_commit.timestamp }}&lt;/span&gt;
            &lt;span class="s"&gt;GIT_SHA=${{ github.sha }}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Deploying to a VPS via SSH
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;deploy&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Deploy to Production&lt;/span&gt;
    &lt;span class="na"&gt;needs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;test-matrix&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;build-push&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ubuntu-24.04&lt;/span&gt;
    &lt;span class="na"&gt;environment&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;production&lt;/span&gt;
      &lt;span class="na"&gt;url&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;https://myapp.example.com&lt;/span&gt;
    &lt;span class="na"&gt;if&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;github.ref == 'refs/heads/main'&lt;/span&gt;

    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Deploy via SSH&lt;/span&gt;
        &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;appleboy/ssh-action@v1&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;host&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.VPS_HOST }}&lt;/span&gt;
          &lt;span class="na"&gt;username&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.VPS_USER }}&lt;/span&gt;
          &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.VPS_SSH_KEY }}&lt;/span&gt;
          &lt;span class="na"&gt;port&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;22&lt;/span&gt;
          &lt;span class="na"&gt;script&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
            &lt;span class="s"&gt;set -e&lt;/span&gt;
            &lt;span class="s"&gt;cd /opt/myapp&lt;/span&gt;

            &lt;span class="s"&gt;# pull latest image&lt;/span&gt;
            &lt;span class="s"&gt;echo "${{ secrets.GHCR_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin&lt;/span&gt;
            &lt;span class="s"&gt;docker pull ghcr.io/${{ github.repository }}:sha-${{ github.sha }}&lt;/span&gt;

            &lt;span class="s"&gt;# snapshot last-good image before swapping&lt;/span&gt;
            &lt;span class="s"&gt;docker tag ghcr.io/${{ github.repository }}:latest                        ghcr.io/${{ github.repository }}:last-good 2&amp;gt;/dev/null || true&lt;/span&gt;

            &lt;span class="s"&gt;# atomic swap&lt;/span&gt;
            &lt;span class="s"&gt;docker compose up -d --no-deps app&lt;/span&gt;
            &lt;span class="s"&gt;docker image prune -f&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Secrets and Environment Variables
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# NEVER hardcode secrets. Use GitHub Secrets.&lt;/span&gt;
&lt;span class="c1"&gt;# Settings → Secrets and variables → Actions&lt;/span&gt;

&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;deploy&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Run migrations&lt;/span&gt;
        &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;DATABASE_URL&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.DATABASE_URL }}&lt;/span&gt;
          &lt;span class="na"&gt;REDIS_URL&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.REDIS_URL }}&lt;/span&gt;
        &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm run db:migrate&lt;/span&gt;

      &lt;span class="c1"&gt;# pass to Docker build-arg (does NOT embed in final image layers if used correctly)&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;docker/build-push-action@v6&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;build-args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
            &lt;span class="s"&gt;NEXT_PUBLIC_API_URL=${{ vars.NEXT_PUBLIC_API_URL }}&lt;/span&gt;
          &lt;span class="na"&gt;secrets&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
            &lt;span class="s"&gt;DATABASE_URL=${{ secrets.DATABASE_URL }}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Reusable Workflows
&lt;/h2&gt;

&lt;p&gt;Reusable workflows let you define a workflow once and call it from multiple repositories or jobs. They are the DRY principle for CI/CD.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# .github/workflows/_reusable-test.yml&lt;/span&gt;
&lt;span class="na"&gt;on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;workflow_call&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;inputs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;node-version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;required&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
        &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;string&lt;/span&gt;
        &lt;span class="na"&gt;default&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;22'&lt;/span&gt;
    &lt;span class="na"&gt;secrets&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;DATABASE_URL&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;required&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;test&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ubuntu-24.04&lt;/span&gt;
    &lt;span class="na"&gt;services&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;postgres&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;image&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;postgres:16&lt;/span&gt;
        &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;POSTGRES_PASSWORD&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;test&lt;/span&gt;
          &lt;span class="na"&gt;POSTGRES_DB&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;testdb&lt;/span&gt;
        &lt;span class="na"&gt;options&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;&amp;gt;-&lt;/span&gt;
          &lt;span class="s"&gt;--health-cmd pg_isready&lt;/span&gt;
          &lt;span class="s"&gt;--health-interval 10s&lt;/span&gt;
          &lt;span class="s"&gt;--health-timeout 5s&lt;/span&gt;
          &lt;span class="s"&gt;--health-retries 5&lt;/span&gt;
    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/checkout@v4&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/setup-node@v4&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;node-version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ inputs.node-version }}&lt;/span&gt;
          &lt;span class="na"&gt;cache&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;npm'&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm ci&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm test&lt;/span&gt;
        &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;DATABASE_URL&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.DATABASE_URL }}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;





&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# .github/workflows/ci.yml — calling the reusable workflow&lt;/span&gt;
&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;test&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;./.github/workflows/_reusable-test.yml&lt;/span&gt;
    &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;node-version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;22'&lt;/span&gt;
    &lt;span class="na"&gt;secrets&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;DATABASE_URL&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.DATABASE_URL }}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Self-Hosted Runners
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# run on your own hardware for faster builds or private network access&lt;/span&gt;
&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;deploy-internal&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;self-hosted&lt;/span&gt;         &lt;span class="c1"&gt;# uses any runner with no labels&lt;/span&gt;
    &lt;span class="c1"&gt;# OR target specific runners:&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;self-hosted&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;linux&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;x64&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;production&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/checkout@v4&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm ci&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm run deploy:internal&lt;/span&gt;
        &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;INTERNAL_API_URL&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.INTERNAL_API_URL }}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Register a self-hosted runner at Settings → Actions → Runners → New self-hosted runner. The runner process runs on your machine and polls GitHub for jobs. Label runners to control which jobs run where.&lt;/p&gt;

&lt;h2&gt;
  
  
  A Complete Pipeline: Test, Build, Deploy, Verify
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# .github/workflows/deploy.yml&lt;/span&gt;
&lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Deploy Production&lt;/span&gt;

&lt;span class="na"&gt;on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;push&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;branches&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;main&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

&lt;span class="na"&gt;concurrency&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;group&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;deploy-production&lt;/span&gt;
  &lt;span class="na"&gt;cancel-in-progress&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;

&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;test&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;./.github/workflows/_reusable-test.yml&lt;/span&gt;
    &lt;span class="na"&gt;secrets&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;inherit&lt;/span&gt;

  &lt;span class="na"&gt;build&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;needs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;test&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ubuntu-24.04&lt;/span&gt;
    &lt;span class="na"&gt;outputs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;image-tag&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ steps.meta.outputs.version }}&lt;/span&gt;
    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/checkout@v4&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;docker/setup-buildx-action@v3&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;docker/login-action@v3&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;registry&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ghcr.io&lt;/span&gt;
          &lt;span class="na"&gt;username&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ github.actor }}&lt;/span&gt;
          &lt;span class="na"&gt;password&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.GITHUB_TOKEN }}&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;meta&lt;/span&gt;
        &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;docker/metadata-action@v5&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;images&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ghcr.io/${{ github.repository }}&lt;/span&gt;
          &lt;span class="na"&gt;tags&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;type=sha,prefix=sha-&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;docker/build-push-action@v6&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;push&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
          &lt;span class="na"&gt;tags&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ steps.meta.outputs.tags }}&lt;/span&gt;
          &lt;span class="na"&gt;cache-from&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;type=gha&lt;/span&gt;
          &lt;span class="na"&gt;cache-to&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;type=gha,mode=max&lt;/span&gt;

  &lt;span class="na"&gt;deploy&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;needs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;build&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ubuntu-24.04&lt;/span&gt;
    &lt;span class="na"&gt;environment&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;production&lt;/span&gt;
    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;appleboy/ssh-action@v1&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;host&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.VPS_HOST }}&lt;/span&gt;
          &lt;span class="na"&gt;username&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;deploy&lt;/span&gt;
          &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ secrets.VPS_SSH_KEY }}&lt;/span&gt;
          &lt;span class="na"&gt;script&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
            &lt;span class="s"&gt;cd /opt/myapp&lt;/span&gt;
            &lt;span class="s"&gt;IMAGE="ghcr.io/${{ github.repository }}:sha-${{ github.sha }}"&lt;/span&gt;
            &lt;span class="s"&gt;docker pull "$IMAGE"&lt;/span&gt;
            &lt;span class="s"&gt;IMAGE="$IMAGE" docker compose up -d --no-deps app&lt;/span&gt;

  &lt;span class="na"&gt;verify&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;needs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;deploy&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ubuntu-24.04&lt;/span&gt;
    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Health check&lt;/span&gt;
        &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
          &lt;span class="s"&gt;for i in 1 2 3 4 5; do&lt;/span&gt;
            &lt;span class="s"&gt;STATUS=$(curl -s -o /dev/null -w "%{http_code}" https://myapp.example.com/healthz)&lt;/span&gt;
            &lt;span class="s"&gt;if [ "$STATUS" = "200" ]; then&lt;/span&gt;
              &lt;span class="s"&gt;echo "Health check passed"&lt;/span&gt;
              &lt;span class="s"&gt;exit 0&lt;/span&gt;
            &lt;span class="s"&gt;fi&lt;/span&gt;
            &lt;span class="s"&gt;echo "Attempt $i: got $STATUS, retrying in 10s..."&lt;/span&gt;
            &lt;span class="s"&gt;sleep 10&lt;/span&gt;
          &lt;span class="s"&gt;done&lt;/span&gt;
          &lt;span class="s"&gt;echo "Health check failed after 5 attempts"&lt;/span&gt;
          &lt;span class="s"&gt;exit 1&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  People Also Ask
&lt;/h2&gt;

&lt;h3&gt;
  
  
  How do I prevent GitHub Actions from running on draft pull requests?
&lt;/h3&gt;

&lt;p&gt;Add a filter to your &lt;code&gt;pull_request&lt;/code&gt; trigger: &lt;code&gt;types: [opened, synchronize, reopened]&lt;/code&gt;. Draft PRs only trigger on &lt;code&gt;opened&lt;/code&gt; and &lt;code&gt;converted_to_draft&lt;/code&gt; — removing &lt;code&gt;opened&lt;/code&gt; from the list does not help since drafts fire on it. The correct approach is to add a conditional: &lt;code&gt;if: github.event.pull_request.draft == false&lt;/code&gt; on the job or workflow level.&lt;/p&gt;

&lt;h3&gt;
  
  
  What is the difference between &lt;code&gt;secrets.GITHUB_TOKEN&lt;/code&gt; and a personal access token?
&lt;/h3&gt;

&lt;p&gt;&lt;code&gt;GITHUB_TOKEN&lt;/code&gt; is automatically provisioned by GitHub Actions for every run — it is scoped to the current repository and expires when the run ends. It is sufficient for pushing Docker images to GHCR, creating releases, and commenting on PRs. A PAT (personal access token) or fine-grained token is needed when you need to access other repositories, create webhooks, or perform actions that exceed the default token's permissions. Always prefer &lt;code&gt;GITHUB_TOKEN&lt;/code&gt; where possible — it is the principle of least privilege.&lt;/p&gt;

&lt;h3&gt;
  
  
  How do I speed up npm install in GitHub Actions?
&lt;/h3&gt;

&lt;h2&gt;
  
  
  Use &lt;code&gt;actions/setup-node&lt;/code&gt; with &lt;code&gt;cache: 'npm'&lt;/code&gt; — this caches the npm global cache keyed on &lt;code&gt;package-lock.json&lt;/code&gt;. Also use &lt;code&gt;npm ci&lt;/code&gt; (not &lt;code&gt;npm install&lt;/code&gt;) in CI — it skips the dependency resolution step, uses the lockfile directly, and is 2–3x faster. For monorepos, cache the individual package directories with &lt;code&gt;actions/cache&lt;/code&gt; using a hash of all &lt;code&gt;package-lock.json&lt;/code&gt; files as the key.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/github-actions-ci-cd-nodejs-complete-pipeline-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>githubactions</category>
      <category>dockerdeployment</category>
      <category>reusableworkflows</category>
    </item>
    <item>
      <title>SQL Performance: Indexing, Query Tuning &amp; Explain Plans (Developer Guide)</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Thu, 21 May 2026 16:00:15 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/sql-performance-indexing-query-tuning-explain-plans-developer-guide-4058</link>
      <guid>https://forem.com/akaranjkar08/sql-performance-indexing-query-tuning-explain-plans-developer-guide-4058</guid>
      <description>&lt;p&gt;&lt;strong&gt;A missing index on a foreign key column can turn a 5ms query into a 5-second table scan. A correlated subquery in a WHERE clause can multiply your query time by the number of rows. An ORM that generates N+1 queries can bring down a production API under moderate load. SQL performance problems are almost always fixable — the hard part is knowing where to look. This guide is that map.&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;All examples use PostgreSQL 16 syntax. The concepts apply to MySQL, SQLite, and most relational databases.&lt;/p&gt;

&lt;h2&gt;
  
  
  How PostgreSQL Picks a Query Plan
&lt;/h2&gt;

&lt;p&gt;Before optimizing, understand what the planner does. PostgreSQL maintains statistics about tables and uses a cost-based optimizer to choose among many possible query plans. It estimates row counts, considers available indexes, and picks the plan with the lowest estimated cost. The planner is usually right — when it is wrong, it is almost always because statistics are stale or misleading.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight sql"&gt;&lt;code&gt;&lt;span class="c1"&gt;-- always run ANALYZE before investigating slow queries&lt;/span&gt;
&lt;span class="k"&gt;ANALYZE&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;-- basic EXPLAIN (shows plan, no execution)&lt;/span&gt;
&lt;span class="k"&gt;EXPLAIN&lt;/span&gt; &lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;customer_id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;42&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;-- EXPLAIN ANALYZE (runs the query, shows actual vs estimated rows)&lt;/span&gt;
&lt;span class="k"&gt;EXPLAIN&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;ANALYZE&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;BUFFERS&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;FORMAT&lt;/span&gt; &lt;span class="nb"&gt;TEXT&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;c&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;email&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;
&lt;span class="k"&gt;JOIN&lt;/span&gt; &lt;span class="n"&gt;customers&lt;/span&gt; &lt;span class="k"&gt;c&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="k"&gt;c&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;customer_id&lt;/span&gt;
&lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;status&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s1"&gt;'pending'&lt;/span&gt;
  &lt;span class="k"&gt;AND&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;NOW&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="n"&gt;INTERVAL&lt;/span&gt; &lt;span class="s1"&gt;'7 days'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The output to look for: &lt;code&gt;Seq Scan&lt;/code&gt; (table scan — usually bad on large tables), &lt;code&gt;Index Scan&lt;/code&gt; (good), &lt;code&gt;Bitmap Index Scan&lt;/code&gt; (good for low selectivity), and &lt;code&gt;Hash Join&lt;/code&gt; vs &lt;code&gt;Nested Loop&lt;/code&gt; vs &lt;code&gt;Merge Join&lt;/code&gt;. A large discrepancy between "rows estimated" and "rows actual" means the planner has bad statistics.&lt;/p&gt;

&lt;h2&gt;
  
  
  B-Tree Indexes: The Foundation
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight sql"&gt;&lt;code&gt;&lt;span class="c1"&gt;-- basic single-column index&lt;/span&gt;
&lt;span class="k"&gt;CREATE&lt;/span&gt; &lt;span class="k"&gt;INDEX&lt;/span&gt; &lt;span class="n"&gt;idx_orders_customer_id&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;customer_id&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

&lt;span class="c1"&gt;-- index on a frequently filtered status column&lt;/span&gt;
&lt;span class="k"&gt;CREATE&lt;/span&gt; &lt;span class="k"&gt;INDEX&lt;/span&gt; &lt;span class="n"&gt;idx_orders_status&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;status&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

&lt;span class="c1"&gt;-- partial index — only index the rows you actually query&lt;/span&gt;
&lt;span class="c1"&gt;-- much smaller, faster to maintain&lt;/span&gt;
&lt;span class="k"&gt;CREATE&lt;/span&gt; &lt;span class="k"&gt;INDEX&lt;/span&gt; &lt;span class="n"&gt;idx_orders_pending&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;created_at&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;status&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s1"&gt;'pending'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;-- unique index (enforces uniqueness + faster lookups)&lt;/span&gt;
&lt;span class="k"&gt;CREATE&lt;/span&gt; &lt;span class="k"&gt;UNIQUE&lt;/span&gt; &lt;span class="k"&gt;INDEX&lt;/span&gt; &lt;span class="n"&gt;idx_users_email&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;users&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;lower&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;email&lt;/span&gt;&lt;span class="p"&gt;));&lt;/span&gt;

&lt;span class="c1"&gt;-- expression index — index a computed value&lt;/span&gt;
&lt;span class="k"&gt;CREATE&lt;/span&gt; &lt;span class="k"&gt;INDEX&lt;/span&gt; &lt;span class="n"&gt;idx_users_email_lower&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;users&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;lower&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;email&lt;/span&gt;&lt;span class="p"&gt;));&lt;/span&gt;
&lt;span class="c1"&gt;-- now this query uses the index:&lt;/span&gt;
&lt;span class="c1"&gt;-- SELECT * FROM users WHERE lower(email) = 'user@example.com';&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Composite Indexes: Column Order Matters
&lt;/h2&gt;

&lt;p&gt;A composite index on &lt;code&gt;(a, b, c)&lt;/code&gt; can satisfy queries on &lt;code&gt;a&lt;/code&gt;, &lt;code&gt;a, b&lt;/code&gt;, and &lt;code&gt;a, b, c&lt;/code&gt; — but NOT on &lt;code&gt;b&lt;/code&gt; alone or &lt;code&gt;c&lt;/code&gt; alone. The leading column rule is the most commonly misunderstood fact about composite indexes.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight sql"&gt;&lt;code&gt;&lt;span class="c1"&gt;-- this index supports:&lt;/span&gt;
&lt;span class="c1"&gt;-- WHERE status = 'pending'                          ✓&lt;/span&gt;
&lt;span class="c1"&gt;-- WHERE status = 'pending' AND created_at &amp;gt; ...    ✓&lt;/span&gt;
&lt;span class="c1"&gt;-- WHERE status = 'pending' AND created_at &amp;gt; ... AND customer_id = 42  ✓&lt;/span&gt;
&lt;span class="c1"&gt;-- WHERE created_at &amp;gt; ...                            ✗ (can't skip status)&lt;/span&gt;
&lt;span class="k"&gt;CREATE&lt;/span&gt; &lt;span class="k"&gt;INDEX&lt;/span&gt; &lt;span class="n"&gt;idx_orders_status_created_customer&lt;/span&gt;
  &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;status&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;customer_id&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

&lt;span class="c1"&gt;-- covering index — includes all columns the query needs, zero heap fetches&lt;/span&gt;
&lt;span class="k"&gt;CREATE&lt;/span&gt; &lt;span class="k"&gt;INDEX&lt;/span&gt; &lt;span class="n"&gt;idx_orders_covering&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;customer_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;status&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="n"&gt;INCLUDE&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

&lt;span class="c1"&gt;-- query that uses the covering index with no heap access:&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt;
&lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;customer_id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;42&lt;/span&gt; &lt;span class="k"&gt;AND&lt;/span&gt; &lt;span class="n"&gt;status&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s1"&gt;'shipped'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Reading EXPLAIN ANALYZE Output
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight sql"&gt;&lt;code&gt;&lt;span class="k"&gt;EXPLAIN&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;ANALYZE&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;BUFFERS&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;SUM&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;quantity&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;unit_price&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;revenue&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;order_items&lt;/span&gt; &lt;span class="n"&gt;oi&lt;/span&gt;
&lt;span class="k"&gt;JOIN&lt;/span&gt; &lt;span class="n"&gt;products&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;product_id&lt;/span&gt;
&lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="k"&gt;BETWEEN&lt;/span&gt; &lt;span class="s1"&gt;'2026-01-01'&lt;/span&gt; &lt;span class="k"&gt;AND&lt;/span&gt; &lt;span class="s1"&gt;'2026-03-31'&lt;/span&gt;
&lt;span class="k"&gt;GROUP&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;
&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;revenue&lt;/span&gt; &lt;span class="k"&gt;DESC&lt;/span&gt;
&lt;span class="k"&gt;LIMIT&lt;/span&gt; &lt;span class="mi"&gt;20&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="cm"&gt;/*
 Sample output sections to read:

 -&amp;gt; Hash Join  (cost=1234.56..5678.90 rows=10000 width=48)
              (actual time=45.123..98.456 rows=8734 loops=1)
   Hash Cond: (oi.product_id = p.id)
   Buffers: shared hit=1023 read=234

   -&amp;gt; Bitmap Heap Scan on order_items oi
         (actual time=12.3..34.5 rows=92345 loops=1)
      Recheck Cond: (created_at BETWEEN ...)
      -&amp;gt;  Bitmap Index Scan on idx_oi_created_at
            (actual time=8.9..8.9 rows=92345 loops=1)

 Planning Time: 2.1 ms
 Execution Time: 102.3 ms
*/&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Key metrics: &lt;code&gt;actual time&lt;/code&gt; is the real wall time. &lt;code&gt;rows&lt;/code&gt; discrepancy is your optimization signal. &lt;code&gt;Buffers: read=N&lt;/code&gt; means disk I/O — large values indicate missing indexes or cold cache.&lt;/p&gt;

&lt;h2&gt;
  
  
  Eliminating N+1 Queries
&lt;/h2&gt;

&lt;p&gt;The N+1 problem happens when you fetch a list of records, then run one query per record to fetch related data. In SQL, the fix is always a JOIN.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight sql"&gt;&lt;code&gt;&lt;span class="c1"&gt;-- BAD: 1 query for orders + N queries for customers&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;status&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s1"&gt;'pending'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="c1"&gt;-- then for each order:&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;customers&lt;/span&gt; &lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="o"&gt;?&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;-- GOOD: single query with JOIN&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt;
  &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;created_at&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="k"&gt;c&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;         &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;customer_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="k"&gt;c&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;email&lt;/span&gt;      &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;customer_email&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="k"&gt;c&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;first_name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="k"&gt;c&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;last_name&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;
&lt;span class="k"&gt;JOIN&lt;/span&gt; &lt;span class="n"&gt;customers&lt;/span&gt; &lt;span class="k"&gt;c&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="k"&gt;c&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;customer_id&lt;/span&gt;
&lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;status&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s1"&gt;'pending'&lt;/span&gt;
&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="k"&gt;DESC&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;





&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight sql"&gt;&lt;code&gt;&lt;span class="c1"&gt;-- fetching nested aggregates without N+1&lt;/span&gt;
&lt;span class="c1"&gt;-- BAD: separate query per order for item count&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;NOW&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="n"&gt;INTERVAL&lt;/span&gt; &lt;span class="s1"&gt;'30 days'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="c1"&gt;-- then: SELECT COUNT(*) FROM order_items WHERE order_id = ?&lt;/span&gt;

&lt;span class="c1"&gt;-- GOOD: aggregate in JOIN&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt;
  &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="k"&gt;COUNT&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;              &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;item_count&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="k"&gt;SUM&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;quantity&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;          &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;total_units&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;
&lt;span class="k"&gt;LEFT&lt;/span&gt; &lt;span class="k"&gt;JOIN&lt;/span&gt; &lt;span class="n"&gt;order_items&lt;/span&gt; &lt;span class="n"&gt;oi&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;order_id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;
&lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;NOW&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="n"&gt;INTERVAL&lt;/span&gt; &lt;span class="s1"&gt;'30 days'&lt;/span&gt;
&lt;span class="k"&gt;GROUP&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;total&lt;/span&gt;
&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;o&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="k"&gt;DESC&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  CTEs vs Subqueries
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight sql"&gt;&lt;code&gt;&lt;span class="c1"&gt;-- subquery in FROM (derived table) — planner can inline and optimize&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;revenue_data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;total_revenue&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;products&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;
&lt;span class="k"&gt;JOIN&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
  &lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="n"&gt;product_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;SUM&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;quantity&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="n"&gt;unit_price&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;total_revenue&lt;/span&gt;
  &lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;order_items&lt;/span&gt;
  &lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;NOW&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="n"&gt;INTERVAL&lt;/span&gt; &lt;span class="s1"&gt;'90 days'&lt;/span&gt;
  &lt;span class="k"&gt;GROUP&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;product_id&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="n"&gt;revenue_data&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;revenue_data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;product_id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;
&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;revenue_data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;total_revenue&lt;/span&gt; &lt;span class="k"&gt;DESC&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;-- CTE — cleaner syntax, same performance in Postgres 12+&lt;/span&gt;
&lt;span class="c1"&gt;-- (CTEs are now inlined by default unless MATERIALIZED is specified)&lt;/span&gt;
&lt;span class="k"&gt;WITH&lt;/span&gt; &lt;span class="n"&gt;revenue_by_product&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
  &lt;span class="k"&gt;SELECT&lt;/span&gt;
    &lt;span class="n"&gt;product_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="k"&gt;SUM&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;quantity&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="n"&gt;unit_price&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;total_revenue&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="k"&gt;COUNT&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;DISTINCT&lt;/span&gt; &lt;span class="n"&gt;order_id&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;   &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;order_count&lt;/span&gt;
  &lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;order_items&lt;/span&gt;
  &lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;NOW&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="n"&gt;INTERVAL&lt;/span&gt; &lt;span class="s1"&gt;'90 days'&lt;/span&gt;
  &lt;span class="k"&gt;GROUP&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;product_id&lt;/span&gt;
&lt;span class="p"&gt;),&lt;/span&gt;
&lt;span class="n"&gt;top_products&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
  &lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="n"&gt;product_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;total_revenue&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;order_count&lt;/span&gt;
  &lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;revenue_by_product&lt;/span&gt;
  &lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;total_revenue&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="mi"&gt;1000&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;tp&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;total_revenue&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;tp&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;order_count&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;top_products&lt;/span&gt; &lt;span class="n"&gt;tp&lt;/span&gt;
&lt;span class="k"&gt;JOIN&lt;/span&gt; &lt;span class="n"&gt;products&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;tp&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;product_id&lt;/span&gt;
&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;tp&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;total_revenue&lt;/span&gt; &lt;span class="k"&gt;DESC&lt;/span&gt;
&lt;span class="k"&gt;LIMIT&lt;/span&gt; &lt;span class="mi"&gt;50&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;-- force materialization when the CTE result is expensive + reused&lt;/span&gt;
&lt;span class="k"&gt;WITH&lt;/span&gt; &lt;span class="n"&gt;MATERIALIZED&lt;/span&gt; &lt;span class="n"&gt;expensive_aggregation&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
  &lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="n"&gt;customer_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;AVG&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;avg_order_value&lt;/span&gt;
  &lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt;
  &lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;NOW&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="n"&gt;INTERVAL&lt;/span&gt; &lt;span class="s1"&gt;'1 year'&lt;/span&gt;
  &lt;span class="k"&gt;GROUP&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;customer_id&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="k"&gt;c&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;email&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;ea&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;avg_order_value&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;expensive_aggregation&lt;/span&gt; &lt;span class="n"&gt;ea&lt;/span&gt;
&lt;span class="k"&gt;JOIN&lt;/span&gt; &lt;span class="n"&gt;customers&lt;/span&gt; &lt;span class="k"&gt;c&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="k"&gt;c&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;ea&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;customer_id&lt;/span&gt;
&lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;ea&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;avg_order_value&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="mi"&gt;200&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Window Functions
&lt;/h2&gt;

&lt;p&gt;Window functions compute a value across a set of rows related to the current row — without collapsing them into a single GROUP BY result. They are one of the most powerful SQL features for analytics.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight sql"&gt;&lt;code&gt;&lt;span class="c1"&gt;-- running total&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt;
  &lt;span class="n"&gt;created_at&lt;/span&gt;&lt;span class="p"&gt;::&lt;/span&gt;&lt;span class="nb"&gt;date&lt;/span&gt;      &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="nb"&gt;date&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="k"&gt;SUM&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;            &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;daily_revenue&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="k"&gt;SUM&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;SUM&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt; &lt;span class="n"&gt;OVER&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt;&lt;span class="p"&gt;::&lt;/span&gt;&lt;span class="nb"&gt;date&lt;/span&gt;
    &lt;span class="k"&gt;ROWS&lt;/span&gt; &lt;span class="n"&gt;UNBOUNDED&lt;/span&gt; &lt;span class="k"&gt;PRECEDING&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;                     &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;cumulative_revenue&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt;
&lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;=&lt;/span&gt; &lt;span class="s1"&gt;'2026-01-01'&lt;/span&gt;
&lt;span class="k"&gt;GROUP&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt;&lt;span class="p"&gt;::&lt;/span&gt;&lt;span class="nb"&gt;date&lt;/span&gt;
&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="nb"&gt;date&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;-- rank products by revenue within each category&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt;
  &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;category&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="k"&gt;SUM&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;quantity&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;unit_price&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;          &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;revenue&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;RANK&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="n"&gt;OVER&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="k"&gt;PARTITION&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;category&lt;/span&gt;
    &lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="k"&gt;SUM&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;quantity&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;unit_price&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;DESC&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;                                          &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;rank_in_category&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;products&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;
&lt;span class="k"&gt;JOIN&lt;/span&gt; &lt;span class="n"&gt;order_items&lt;/span&gt; &lt;span class="n"&gt;oi&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;oi&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;product_id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;
&lt;span class="k"&gt;GROUP&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;category&lt;/span&gt;
&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;p&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;category&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;rank_in_category&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;-- compare to previous period (LAG)&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt;
  &lt;span class="k"&gt;month&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;revenue&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;LAG&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;revenue&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="n"&gt;OVER&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="k"&gt;month&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;  &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;prev_month_revenue&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;ROUND&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;revenue&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="n"&gt;LAG&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;revenue&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="n"&gt;OVER&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="k"&gt;month&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
    &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="k"&gt;NULLIF&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;LAG&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;revenue&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="n"&gt;OVER&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="k"&gt;month&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mi"&gt;100&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="mi"&gt;2&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;                                     &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;pct_change&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
  &lt;span class="k"&gt;SELECT&lt;/span&gt;
    &lt;span class="n"&gt;DATE_TRUNC&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s1"&gt;'month'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="k"&gt;month&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="k"&gt;SUM&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;total&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;                      &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;revenue&lt;/span&gt;
  &lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt;
  &lt;span class="k"&gt;GROUP&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="n"&gt;monthly&lt;/span&gt;
&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="k"&gt;month&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;-- deduplicate: keep latest record per customer&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="k"&gt;DISTINCT&lt;/span&gt; &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;customer_id&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="n"&gt;customer_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;id&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;order_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;total&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;orders&lt;/span&gt;
&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;customer_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;created_at&lt;/span&gt; &lt;span class="k"&gt;DESC&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Index Maintenance
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight sql"&gt;&lt;code&gt;&lt;span class="c1"&gt;-- find unused indexes (waste space, slow writes)&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt;
  &lt;span class="n"&gt;schemaname&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;tablename&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;indexname&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;idx_scan&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;pg_size_pretty&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;pg_relation_size&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;indexrelid&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;index_size&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;pg_stat_user_indexes&lt;/span&gt;
&lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;idx_scan&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;
  &lt;span class="k"&gt;AND&lt;/span&gt; &lt;span class="n"&gt;indexrelname&lt;/span&gt; &lt;span class="k"&gt;NOT&lt;/span&gt; &lt;span class="k"&gt;LIKE&lt;/span&gt; &lt;span class="s1"&gt;'pg_%'&lt;/span&gt;
&lt;span class="k"&gt;ORDER&lt;/span&gt; &lt;span class="k"&gt;BY&lt;/span&gt; &lt;span class="n"&gt;pg_relation_size&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;indexrelid&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;DESC&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="c1"&gt;-- find missing indexes on foreign keys&lt;/span&gt;
&lt;span class="k"&gt;SELECT&lt;/span&gt;
  &lt;span class="n"&gt;tc&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;table_name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;kcu&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;column_name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="n"&gt;ccu&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;table_name&lt;/span&gt; &lt;span class="k"&gt;AS&lt;/span&gt; &lt;span class="n"&gt;references_table&lt;/span&gt;
&lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;information_schema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;table_constraints&lt;/span&gt; &lt;span class="n"&gt;tc&lt;/span&gt;
&lt;span class="k"&gt;JOIN&lt;/span&gt; &lt;span class="n"&gt;information_schema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;key_column_usage&lt;/span&gt; &lt;span class="n"&gt;kcu&lt;/span&gt;
  &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;tc&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;constraint_name&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;kcu&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;constraint_name&lt;/span&gt;
&lt;span class="k"&gt;JOIN&lt;/span&gt; &lt;span class="n"&gt;information_schema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;constraint_column_usage&lt;/span&gt; &lt;span class="n"&gt;ccu&lt;/span&gt;
  &lt;span class="k"&gt;ON&lt;/span&gt; &lt;span class="n"&gt;tc&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;constraint_name&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;ccu&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;constraint_name&lt;/span&gt;
&lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;tc&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;constraint_type&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s1"&gt;'FOREIGN KEY'&lt;/span&gt;
  &lt;span class="k"&gt;AND&lt;/span&gt; &lt;span class="k"&gt;NOT&lt;/span&gt; &lt;span class="k"&gt;EXISTS&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="k"&gt;SELECT&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt; &lt;span class="k"&gt;FROM&lt;/span&gt; &lt;span class="n"&gt;pg_indexes&lt;/span&gt;
    &lt;span class="k"&gt;WHERE&lt;/span&gt; &lt;span class="n"&gt;tablename&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;tc&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;table_name&lt;/span&gt;
      &lt;span class="k"&gt;AND&lt;/span&gt; &lt;span class="n"&gt;indexdef&lt;/span&gt; &lt;span class="k"&gt;LIKE&lt;/span&gt; &lt;span class="s1"&gt;'%'&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="n"&gt;kcu&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;column_name&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="s1"&gt;'%'&lt;/span&gt;
  &lt;span class="p"&gt;);&lt;/span&gt;

&lt;span class="c1"&gt;-- rebuild bloated indexes concurrently (no table lock)&lt;/span&gt;
&lt;span class="k"&gt;REINDEX&lt;/span&gt; &lt;span class="k"&gt;INDEX&lt;/span&gt; &lt;span class="n"&gt;CONCURRENTLY&lt;/span&gt; &lt;span class="n"&gt;idx_orders_customer_id&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  People Also Ask
&lt;/h2&gt;

&lt;h3&gt;
  
  
  When should I use a partial index instead of a full index?
&lt;/h3&gt;

&lt;p&gt;Use a partial index when your queries consistently filter on a specific condition — like &lt;code&gt;WHERE status = 'pending'&lt;/code&gt; or &lt;code&gt;WHERE deleted_at IS NULL&lt;/code&gt;. A partial index only indexes rows matching the condition, so it is smaller (faster to build, cheaper to maintain) and has higher selectivity (more likely to be used by the planner). The tradeoff is that it only helps queries that include the matching WHERE clause.&lt;/p&gt;

&lt;h3&gt;
  
  
  Why does adding an index sometimes make queries slower?
&lt;/h3&gt;

&lt;p&gt;For very low-selectivity queries (e.g., &lt;code&gt;WHERE status IN ('a', 'b', 'c')&lt;/code&gt; matching 80% of rows), a sequential scan is actually faster than an index scan because the index forces random I/O to fetch each heap page individually. The planner knows this and will choose a seq scan. You can force it with hints in development, but in production you should trust the planner — and investigate its statistics if you think it is wrong.&lt;/p&gt;

&lt;h3&gt;
  
  
  What is the difference between EXPLAIN and EXPLAIN ANALYZE?
&lt;/h3&gt;

&lt;h2&gt;
  
  
  EXPLAIN shows the query plan the planner &lt;em&gt;would&lt;/em&gt; use — it does not execute the query. EXPLAIN ANALYZE actually runs the query and shows both the estimated and actual row counts and timings. Always use EXPLAIN ANALYZE with BUFFERS (&lt;code&gt;EXPLAIN (ANALYZE, BUFFERS)&lt;/code&gt;) when debugging performance issues so you can see disk I/O. Be careful: EXPLAIN ANALYZE on a DELETE or UPDATE will actually execute those statements, so wrap them in a transaction you roll back if needed.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/sql-performance-optimization-indexing-query-tuning-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>sqlperformance</category>
      <category>postgresqlindexing</category>
      <category>sqlexplain</category>
      <category>n1query</category>
    </item>
    <item>
      <title>Web Scraping with Node.js: Puppeteer vs Cheerio (Complete 2026 Guide)</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Thu, 21 May 2026 16:00:10 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/web-scraping-with-nodejs-puppeteer-vs-cheerio-complete-2026-guide-4hha</link>
      <guid>https://forem.com/akaranjkar08/web-scraping-with-nodejs-puppeteer-vs-cheerio-complete-2026-guide-4hha</guid>
      <description>&lt;p&gt;&lt;strong&gt;Web scraping is one of those skills that looks simple until you hit your first JavaScript-rendered page, your first CAPTCHA, or your first IP ban. Cheerio handles 70% of scraping tasks with almost zero overhead. Puppeteer handles the rest. This guide covers both in depth — when to use each, how to build scrapers that survive real sites, and how to extract structured data reliably at scale.&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;If you are building data pipelines or automation workflows, check out the &lt;a href="https://dev.to/tools/"&gt;WOWHOW Tools library&lt;/a&gt; for pre-built utilities, and &lt;a href="https://dev.to/browse"&gt;browse the full catalog&lt;/a&gt; for data engineering starter kits.&lt;/p&gt;

&lt;h2&gt;
  
  
  Cheerio: Fast Static Scraping
&lt;/h2&gt;

&lt;p&gt;Cheerio loads raw HTML and gives you a jQuery-like API to query it. No browser, no JavaScript execution — just a DOM parser. It is 10–50x faster than Puppeteer for static pages and uses a fraction of the memory.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="nx"&gt;cheerio&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;cheerio&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;scrapeHackerNews&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;response&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;headers&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;User-Agent&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Mozilla/5.0 (compatible; research-bot/1.0)&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;html&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;response&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;text&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;$&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;cheerio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;load&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;html&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;stories&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;Array&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[]&lt;/span&gt;

  &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.athing&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;each&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;i&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;rank&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;parseInt&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.rank&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;text&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;replace&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;''&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;titleEl&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.titleline &amp;gt; a&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;first&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;title&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;titleEl&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;text&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;trim&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;href&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;titleEl&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;attr&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;href&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="dl"&gt;''&lt;/span&gt;

    &lt;span class="c1"&gt;// points are in the NEXT sibling row&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;subtext&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;next&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.spacer&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;next&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;points&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;parseInt&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;subtext&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.score&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;text&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;

    &lt;span class="nx"&gt;stories&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;push&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;rank&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;title&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;url&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;href&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;points&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;

  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;stories&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Cheerio Selector Patterns
&lt;/h2&gt;

&lt;p&gt;Mastering selectors is the key skill. Here are the patterns you will use most:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="nx"&gt;cheerio&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;cheerio&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;demonstrateSelectors&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;html&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;$&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;cheerio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;load&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;html&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

  &lt;span class="c1"&gt;// --- attribute selectors&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;dataLinks&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;a[data-track]&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;           &lt;span class="c1"&gt;// has attribute&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;exactMatch&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;input[type="submit"]&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;   &lt;span class="c1"&gt;// exact value&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;contains&lt;/span&gt;   &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;[class*="product-card"]&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="c1"&gt;// contains substring&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;startsWith&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;[href^="https://"]&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;      &lt;span class="c1"&gt;// starts with&lt;/span&gt;

  &lt;span class="c1"&gt;// --- positional pseudo-selectors&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;firstCard&lt;/span&gt;  &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.product-card&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;first&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;lastCard&lt;/span&gt;   &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.product-card&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;last&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;thirdCard&lt;/span&gt;  &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.product-card&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;eq&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;    &lt;span class="c1"&gt;// 0-indexed&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;evenRows&lt;/span&gt;   &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;tr:nth-child(even)&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

  &lt;span class="c1"&gt;// --- traversal&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;parent&lt;/span&gt;       &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.price&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;parent&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;closestForm&lt;/span&gt;  &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;input&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;closest&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;form&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;siblings&lt;/span&gt;     &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;h2&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;siblings&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;p&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;nextSibling&lt;/span&gt;  &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.title&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;next&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;allChildren&lt;/span&gt;  &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.card&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;children&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

  &lt;span class="c1"&gt;// --- extracting data&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;text&lt;/span&gt;    &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;h1&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;text&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;trim&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;html2&lt;/span&gt;   &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.description&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;html&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;        &lt;span class="c1"&gt;// inner HTML as string&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;href&lt;/span&gt;    &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;a.cta&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;attr&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;href&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;allHrefs&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;a&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;_&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;attr&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;href&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)).&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

  &lt;span class="c1"&gt;// --- filtering&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;nonEmpty&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;p&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;filter&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;_&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;text&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;trim&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nx"&gt;length&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;withPrice&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.item&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;filter&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;_&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.price&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nx"&gt;length&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;text&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;href&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;allHrefs&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Puppeteer: Dynamic Page Scraping
&lt;/h2&gt;

&lt;p&gt;Use Puppeteer when the content you need is rendered by JavaScript after page load — single-page apps, infinite scroll, lazy-loaded images, login-gated content.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;puppeteer&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;Browser&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;Page&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;puppeteer&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;launchBrowser&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;puppeteer&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;launch&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="na"&gt;headless&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;--no-sandbox&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;--disable-setuid-sandbox&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;--disable-dev-shm-usage&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;--disable-gpu&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;],&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;scrapeDynamicPage&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;browser&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;launchBrowser&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;page&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;browser&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;newPage&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

  &lt;span class="k"&gt;try&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// block images/fonts to speed up loads&lt;/span&gt;
    &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;page&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestInterception&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="nx"&gt;page&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;on&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;request&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;image&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;font&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;media&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nf"&gt;includes&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;resourceType&lt;/span&gt;&lt;span class="p"&gt;()))&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;abort&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;else&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;continue&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;})&lt;/span&gt;

    &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;page&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;goto&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;waitUntil&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;networkidle2&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;timeout&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;30&lt;/span&gt;&lt;span class="nx"&gt;_000&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;

    &lt;span class="c1"&gt;// wait for a specific element before extracting&lt;/span&gt;
    &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;page&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;waitForSelector&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.product-list&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;timeout&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="nx"&gt;_000&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;

    &lt;span class="c1"&gt;// extract data in page context (runs in browser)&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;items&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;page&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;evaluate&lt;/span&gt;&lt;span class="p"&gt;(()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nb"&gt;Array&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;from&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nb"&gt;document&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;querySelectorAll&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.product-card&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)).&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;({&lt;/span&gt;
        &lt;span class="na"&gt;title&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;querySelector&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.title&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)?.&lt;/span&gt;&lt;span class="nx"&gt;textContent&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nf"&gt;trim&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="dl"&gt;''&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;price&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;querySelector&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.price&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)?.&lt;/span&gt;&lt;span class="nx"&gt;textContent&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nf"&gt;trim&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="dl"&gt;''&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;imageUrl&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;querySelector&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;img&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="nx"&gt;HTMLImageElement&lt;/span&gt; &lt;span class="o"&gt;|&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;)?.&lt;/span&gt;&lt;span class="nx"&gt;src&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="dl"&gt;''&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="p"&gt;}))&lt;/span&gt;
    &lt;span class="p"&gt;})&lt;/span&gt;

    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;items&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;finally&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;browser&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;close&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Handling Infinite Scroll
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;scrapeInfiniteScroll&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;page&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;Page&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;results&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;[]&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[]&lt;/span&gt;
  &lt;span class="kd"&gt;let&lt;/span&gt; &lt;span class="nx"&gt;previousHeight&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;

  &lt;span class="k"&gt;while &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// extract items currently visible&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;newItems&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;page&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;evaluate&lt;/span&gt;&lt;span class="p"&gt;(()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt;
      &lt;span class="nb"&gt;Array&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="k"&gt;from&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nb"&gt;document&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;querySelectorAll&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.item-title&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)).&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;textContent&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nf"&gt;trim&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="dl"&gt;''&lt;/span&gt;
      &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="nx"&gt;results&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;push&lt;/span&gt;&lt;span class="p"&gt;(...&lt;/span&gt;&lt;span class="nx"&gt;newItems&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;slice&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;results&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;length&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;

    &lt;span class="c1"&gt;// scroll to bottom&lt;/span&gt;
    &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;page&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;evaluate&lt;/span&gt;&lt;span class="p"&gt;(()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;window&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;scrollTo&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nb"&gt;document&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;body&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;scrollHeight&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
    &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Promise&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;setTimeout&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;1500&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt; &lt;span class="c1"&gt;// wait for load&lt;/span&gt;

    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;newHeight&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;page&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;evaluate&lt;/span&gt;&lt;span class="p"&gt;(()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;document&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;body&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;scrollHeight&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;newHeight&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="nx"&gt;previousHeight&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;break&lt;/span&gt; &lt;span class="c1"&gt;// no more content&lt;/span&gt;
    &lt;span class="nx"&gt;previousHeight&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;newHeight&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;[...&lt;/span&gt;&lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Set&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;results&lt;/span&gt;&lt;span class="p"&gt;)]&lt;/span&gt; &lt;span class="c1"&gt;// deduplicate&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Rate Limiting — The Most Important Part
&lt;/h2&gt;

&lt;p&gt;Scraping without rate limiting will get you banned. Treat rate limiting as mandatory, not optional.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;RateLimiter&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="nx"&gt;queue&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;Array&lt;/span&gt; &lt;span class="k"&gt;void&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[]&lt;/span&gt;
  &lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="nx"&gt;running&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;

  &lt;span class="nf"&gt;constructor&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="k"&gt;readonly&lt;/span&gt; &lt;span class="nx"&gt;maxConcurrent&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="k"&gt;readonly&lt;/span&gt; &lt;span class="nx"&gt;minDelayMs&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="k"&gt;readonly&lt;/span&gt; &lt;span class="nx"&gt;maxDelayMs&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{}&lt;/span&gt;

  &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="nf"&gt;acquire&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt; &lt;span class="k"&gt;void&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;running&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;maxConcurrent&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Promise&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;resolve&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;queue&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;push&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;resolve&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;running&lt;/span&gt;&lt;span class="o"&gt;++&lt;/span&gt;

    &lt;span class="c1"&gt;// jitter: random delay between min and max&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;delay&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt;
      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;minDelayMs&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;random&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;maxDelayMs&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;minDelayMs&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Promise&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;setTimeout&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;delay&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;

    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;running&lt;/span&gt;&lt;span class="o"&gt;--&lt;/span&gt;
      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;queue&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;shift&lt;/span&gt;&lt;span class="p"&gt;()?.()&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// usage&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;limiter&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;RateLimiter&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;1000&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;3000&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="c1"&gt;// max 2 concurrent, 1-3s delay&lt;/span&gt;

&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;fetchWithRateLimit&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;release&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;limiter&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;acquire&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="k"&gt;try&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;res&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;!&lt;/span&gt;&lt;span class="nx"&gt;res&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;ok&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`HTTP &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{res.status}`&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;res&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;text&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;finally&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nf"&gt;release&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Proxy Rotation
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;proxies&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
  &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;http://proxy1.example.com:8080&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;http://proxy2.example.com:8080&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;http://proxy3.example.com:8080&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;]&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;getProxy&lt;/span&gt;&lt;span class="p"&gt;():&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;proxies&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;floor&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;random&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="nx"&gt;proxies&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;length&lt;/span&gt;&lt;span class="p"&gt;)]&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// with Puppeteer&lt;/span&gt;
&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;launchWithProxy&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;proxy&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;puppeteer&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;launch&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="na"&gt;headless&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;`--proxy-server=&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{proxy}`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;--no-sandbox&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
  &lt;span class="p"&gt;})&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// with fetch (via undici or https-proxy-agent)&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;ProxyAgent&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;fetch&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="nx"&gt;undiciFetch&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;undici&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;fetchViaProxy&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;proxy&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;getProxy&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;dispatcher&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;ProxyAgent&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;proxy&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;res&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;undiciFetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;dispatcher&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;
  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;res&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;text&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Retry Logic with Exponential Backoff
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;withRetry&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
  &lt;span class="nx"&gt;fn&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;maxAttempts&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;3&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;baseDelayMs&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;1000&lt;/span&gt;
&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;for &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kd"&gt;let&lt;/span&gt; &lt;span class="nx"&gt;attempt&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt; &lt;span class="nx"&gt;attempt&lt;/span&gt;  &lt;span class="nf"&gt;setTimeout&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;delay&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="nx"&gt;jitter&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;unreachable&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="c1"&gt;// usage&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;html&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;withRetry&lt;/span&gt;&lt;span class="p"&gt;(()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;fetchWithRateLimit&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;url&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Structured Data Extraction with Zod Validation
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;zod&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="nx"&gt;cheerio&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;cheerio&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;ProductSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;title&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;price&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;positive&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;currency&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;length&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;3&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="na"&gt;inStock&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;boolean&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
  &lt;span class="na"&gt;imageUrl&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;url&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;nullable&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;Product&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;infer&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;extractProduct&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;cheerio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;Cheerio&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;$&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;cheerio&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;CheerioAPI&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nx"&gt;Product&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;priceText&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;[data-price]&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;attr&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;data-price&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;0&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;raw&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;attr&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;data-product-id&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="dl"&gt;''&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;title&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.product-title&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;text&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;trim&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
    &lt;span class="na"&gt;price&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;parseFloat&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;priceText&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
    &lt;span class="na"&gt;currency&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;[data-currency]&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;attr&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;data-currency&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;USD&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;inStock&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;.stock-badge&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;text&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;includes&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;In Stock&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
    &lt;span class="na"&gt;imageUrl&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;$&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;el&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;img&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;attr&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;src&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;ProductSchema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;parse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;raw&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="c1"&gt;// throws ZodError if invalid&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Choosing Between Puppeteer and Cheerio
&lt;/h2&gt;

&lt;p&gt;Use Cheerio when: the HTML you need is in the initial response body, you need speed, or you are running many concurrent requests. Use Puppeteer when: content is loaded by JavaScript after initial render, you need to interact with the page (click, scroll, fill forms), or you need to handle authentication flows.&lt;/p&gt;

&lt;p&gt;A common pattern is to use Cheerio first, and fall back to Puppeteer only when the Cheerio output is empty — this gives you fast paths for static pages and automatic fallback for dynamic ones.&lt;/p&gt;

&lt;h2&gt;
  
  
  People Also Ask
&lt;/h2&gt;

&lt;h3&gt;
  
  
  Is web scraping legal?
&lt;/h3&gt;

&lt;p&gt;It depends on the site's terms of service, what data you are collecting, and your jurisdiction. Publicly available data with no ToS prohibition is generally safe. Scraping behind authentication, storing personal data, or violating a site's ToS can create legal exposure. Always check &lt;code&gt;robots.txt&lt;/code&gt; and the site's ToS before scraping commercially.&lt;/p&gt;

&lt;h3&gt;
  
  
  How do I handle CAPTCHAs in Puppeteer?
&lt;/h3&gt;

&lt;p&gt;For light usage, human-in-the-loop (pause and prompt the user to solve). For automation, CAPTCHA solving services like 2Captcha or CapSolver provide APIs that return solved tokens. Some CAPTCHAs can be avoided entirely by using real browser fingerprints, Puppeteer Stealth, and appropriate rate limiting that mimics human behaviour.&lt;/p&gt;

&lt;h3&gt;
  
  
  What is the difference between &lt;code&gt;waitUntil: 'networkidle0'&lt;/code&gt; and &lt;code&gt;'networkidle2'&lt;/code&gt;?
&lt;/h3&gt;

&lt;h2&gt;
  
  
  &lt;code&gt;networkidle0&lt;/code&gt; waits until there are zero network connections for 500ms — good for pages that stop all requests when fully loaded. &lt;code&gt;networkidle2&lt;/code&gt; waits until there are at most 2 connections for 500ms — better for pages that maintain persistent WebSocket or polling connections. Use &lt;code&gt;networkidle2&lt;/code&gt; as the default and only switch to &lt;code&gt;networkidle0&lt;/code&gt; if you know the page fully quiesces.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/web-scraping-nodejs-puppeteer-cheerio-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>webscraping</category>
      <category>puppeteervs</category>
      <category>nodejsscraping</category>
      <category>puppeteerscraping</category>
    </item>
    <item>
      <title>Build Your First MCP Server in TypeScript: Claude Code Integration Guide</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Thu, 21 May 2026 15:40:41 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/build-your-first-mcp-server-in-typescript-claude-code-integration-guide-1f</link>
      <guid>https://forem.com/akaranjkar08/build-your-first-mcp-server-in-typescript-claude-code-integration-guide-1f</guid>
      <description>&lt;p&gt;&lt;strong&gt;The Model Context Protocol (MCP) crossed 9,400 registered servers in early May 2026. Every one of those servers unlocks a new capability inside Claude Code — file access, database queries, API calls, custom tool chains. Building your own MCP server is the fastest way to make Claude Code understand your stack, your data, and your workflows. This guide walks you through a complete, working server in TypeScript from zero to a running integration.&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;MCP is a JSON-RPC 2.0-based protocol that lets Claude Code call external tools, read resources, and use pre-built prompt templates. The server you build runs as a local process. Claude Code spawns it via stdio or connects via HTTP+SSE. The protocol has three capability types: tools (functions Claude can call), resources (data Claude can read), and prompts (reusable templates). You will build a server that exposes all three.&lt;/p&gt;

&lt;h2&gt;
  
  
  What We Are Building
&lt;/h2&gt;

&lt;p&gt;A database introspection server. Claude Code will be able to: list tables in a SQLite database (tool), read table schemas (resource), and use a pre-built prompt template for generating migration scripts. By the end you will have a fully functional MCP server you can extend for any data source.&lt;/p&gt;

&lt;p&gt;Find ready-made developer toolkits at &lt;a href="https://dev.to/browse"&gt;WOWHOW Browse&lt;/a&gt; and TypeScript starter kits at &lt;a href="https://dev.to/tools/"&gt;WOWHOW Tools&lt;/a&gt;.&lt;/p&gt;

&lt;h2&gt;
  
  
  Project Setup
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="nb"&gt;mkdir &lt;/span&gt;mcp-db-server &lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; &lt;span class="nb"&gt;cd &lt;/span&gt;mcp-db-server
npm init &lt;span class="nt"&gt;-y&lt;/span&gt;
npm &lt;span class="nb"&gt;install&lt;/span&gt; @modelcontextprotocol/sdk better-sqlite3 zod
npm &lt;span class="nb"&gt;install&lt;/span&gt; &lt;span class="nt"&gt;-D&lt;/span&gt; typescript @types/node @types/better-sqlite3 tsx
npx tsc &lt;span class="nt"&gt;--init&lt;/span&gt; &lt;span class="nt"&gt;--target&lt;/span&gt; ES2022 &lt;span class="nt"&gt;--module&lt;/span&gt; Node16 &lt;span class="nt"&gt;--moduleResolution&lt;/span&gt; Node16 &lt;span class="nt"&gt;--strict&lt;/span&gt; &lt;span class="nt"&gt;--outDir&lt;/span&gt; dist
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;@modelcontextprotocol/sdk&lt;/code&gt; package handles all protocol framing, message routing, and capability negotiation. You write handlers; the SDK handles the wire protocol.&lt;/p&gt;

&lt;h2&gt;
  
  
  Server Entry Point
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// src/index.ts&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;Server&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/server/index.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;StdioServerTransport&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/server/stdio.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;CallToolRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;ListResourcesRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;ListToolsRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;ReadResourceRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;GetPromptRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;ListPromptsRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/types.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;Database&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;better-sqlite3&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;zod&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;path&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;node:path&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="c1"&gt;// --- create the server instance&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;server&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Server&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
  &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;db-introspection-server&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;version&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;1.0.0&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{},&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{},&lt;/span&gt;
      &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="c1"&gt;// --- open database (path from env or default)&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;DB_PATH&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;process&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;env&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;DB_PATH&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="nx"&gt;path&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;process&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;cwd&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;dev.sqlite&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Database&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;DB_PATH&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;readonly&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Defining Tools
&lt;/h2&gt;

&lt;p&gt;Tools are functions Claude Code can invoke. Each tool has a name, description, and a JSON Schema for its input parameters. The SDK validates inputs against the schema before calling your handler.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// src/tools.ts&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./index.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;CallToolRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;ListToolsRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/types.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="c1"&gt;// --- list available tools&lt;/span&gt;
&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;ListToolsRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;list_tables&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;List all tables in the SQLite database with row counts&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;inputSchema&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;object&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;properties&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{},&lt;/span&gt;
        &lt;span class="na"&gt;required&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[],&lt;/span&gt;
      &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;query_table&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Run a SELECT query on a specific table (read-only)&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;inputSchema&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;object&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;properties&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;table&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;string&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Name of the table to query&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="p"&gt;},&lt;/span&gt;
          &lt;span class="na"&gt;limit&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;number&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Maximum rows to return (default 10, max 100)&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="na"&gt;default&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="p"&gt;},&lt;/span&gt;
          &lt;span class="na"&gt;where&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;string&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Optional WHERE clause (without the WHERE keyword)&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="na"&gt;required&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;table&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
      &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;describe_table&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Get column definitions and indexes for a table&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;inputSchema&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;object&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;properties&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;table&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;string&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Table name&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="na"&gt;required&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;table&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
      &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;],&lt;/span&gt;
&lt;span class="p"&gt;}))&lt;/span&gt;

&lt;span class="c1"&gt;// --- call tool handler&lt;/span&gt;
&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;CallToolRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;arguments&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;args&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;params&lt;/span&gt;

  &lt;span class="k"&gt;switch &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;name&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;case&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;list_tables&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;tables&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;prepare&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
          &lt;span class="s2"&gt;`SELECT name, (SELECT COUNT(*) FROM main.&lt;/span&gt;&lt;span class="se"&gt;\`\$&lt;/span&gt;&lt;span class="s2"&gt;{name}&lt;/span&gt;&lt;span class="se"&gt;\`&lt;/span&gt;&lt;span class="s2"&gt;) AS row_count
           FROM sqlite_master WHERE type='table' ORDER BY name`&lt;/span&gt;
        &lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;all&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="nb"&gt;Array&lt;/span&gt;

      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;content&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
          &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;text&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="na"&gt;text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;tables&lt;/span&gt;
              &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{t.name} (&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{t.row_count} rows)`&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
              &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;join&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="se"&gt;\n&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
          &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;],&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;case&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;query_table&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;schema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
        &lt;span class="na"&gt;table&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;regex&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sr"&gt;/^&lt;/span&gt;&lt;span class="se"&gt;[&lt;/span&gt;&lt;span class="sr"&gt;a-zA-Z_&lt;/span&gt;&lt;span class="se"&gt;][&lt;/span&gt;&lt;span class="sr"&gt;a-zA-Z0-9_&lt;/span&gt;&lt;span class="se"&gt;]&lt;/span&gt;&lt;span class="sr"&gt;*$/&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
        &lt;span class="na"&gt;limit&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;number&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;int&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;100&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="k"&gt;default&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
        &lt;span class="na"&gt;where&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;optional&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
      &lt;span class="p"&gt;})&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;table&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;limit&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;where&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;schema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;parse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;args&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;sql&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;where&lt;/span&gt;
        &lt;span class="p"&gt;?&lt;/span&gt; &lt;span class="s2"&gt;`SELECT * FROM &lt;/span&gt;&lt;span class="se"&gt;\`\$&lt;/span&gt;&lt;span class="s2"&gt;{table}&lt;/span&gt;&lt;span class="se"&gt;\`&lt;/span&gt;&lt;span class="s2"&gt; WHERE &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{where} LIMIT &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{limit}`&lt;/span&gt;
        &lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`SELECT * FROM &lt;/span&gt;&lt;span class="se"&gt;\`\$&lt;/span&gt;&lt;span class="s2"&gt;{table}&lt;/span&gt;&lt;span class="se"&gt;\`&lt;/span&gt;&lt;span class="s2"&gt; LIMIT &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{limit}`&lt;/span&gt;

      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;rows&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;prepare&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;sql&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;all&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;content&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
          &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;text&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="na"&gt;text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;JSON&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stringify&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;rows&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
          &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;],&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;case&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;describe_table&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;schema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
        &lt;span class="na"&gt;table&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;regex&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sr"&gt;/^&lt;/span&gt;&lt;span class="se"&gt;[&lt;/span&gt;&lt;span class="sr"&gt;a-zA-Z_&lt;/span&gt;&lt;span class="se"&gt;][&lt;/span&gt;&lt;span class="sr"&gt;a-zA-Z0-9_&lt;/span&gt;&lt;span class="se"&gt;]&lt;/span&gt;&lt;span class="sr"&gt;*$/&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
      &lt;span class="p"&gt;})&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;table&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;schema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;parse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;args&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;columns&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;prepare&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`PRAGMA table_info(&lt;/span&gt;&lt;span class="se"&gt;\`\$&lt;/span&gt;&lt;span class="s2"&gt;{table}&lt;/span&gt;&lt;span class="se"&gt;\`&lt;/span&gt;&lt;span class="s2"&gt;)`&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;all&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;indexes&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;prepare&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`PRAGMA index_list(&lt;/span&gt;&lt;span class="se"&gt;\`\$&lt;/span&gt;&lt;span class="s2"&gt;{table}&lt;/span&gt;&lt;span class="se"&gt;\`&lt;/span&gt;&lt;span class="s2"&gt;)`&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;all&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;foreignKeys&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;prepare&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`PRAGMA foreign_key_list(&lt;/span&gt;&lt;span class="se"&gt;\`\$&lt;/span&gt;&lt;span class="s2"&gt;{table}&lt;/span&gt;&lt;span class="se"&gt;\`&lt;/span&gt;&lt;span class="s2"&gt;)`&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;all&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;content&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
          &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;text&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="na"&gt;text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;JSON&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stringify&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;columns&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;indexes&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;foreignKeys&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
          &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;],&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="nl"&gt;default&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
      &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`Unknown tool: &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{name}`&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Defining Resources
&lt;/h2&gt;

&lt;p&gt;Resources are data Claude can read — think of them as files or URLs your server exposes. They are listed via &lt;code&gt;resources/list&lt;/code&gt; and fetched via &lt;code&gt;resources/read&lt;/code&gt;.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// src/resources.ts&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./index.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;ListResourcesRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;ReadResourceRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/types.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;ListResourcesRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;tables&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;
    &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;prepare&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`SELECT name FROM sqlite_master WHERE type='table' ORDER BY name`&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;all&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="nb"&gt;Array&lt;/span&gt;

  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;tables&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;({&lt;/span&gt;
      &lt;span class="na"&gt;uri&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`db://schema/&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{t.name}`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`Schema: &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{t.name}`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`Full DDL and column info for table &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{t.name}`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;mimeType&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;application/json&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;})),&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;

&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;ReadResourceRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;uri&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;params&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;match&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;uri&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;match&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sr"&gt;/^db:&lt;/span&gt;&lt;span class="se"&gt;\/\/&lt;/span&gt;&lt;span class="sr"&gt;schema&lt;/span&gt;&lt;span class="se"&gt;\/([&lt;/span&gt;&lt;span class="sr"&gt;a-zA-Z_&lt;/span&gt;&lt;span class="se"&gt;][&lt;/span&gt;&lt;span class="sr"&gt;a-zA-Z0-9_&lt;/span&gt;&lt;span class="se"&gt;]&lt;/span&gt;&lt;span class="sr"&gt;*&lt;/span&gt;&lt;span class="se"&gt;)&lt;/span&gt;&lt;span class="sr"&gt;$/&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;!&lt;/span&gt;&lt;span class="nx"&gt;match&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`Unsupported resource URI: &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{uri}`&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;table&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;match&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;ddl&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;
    &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;prepare&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`SELECT sql FROM sqlite_master WHERE type='table' AND name=?`&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;table&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;sql&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;|&lt;/span&gt; &lt;span class="kc"&gt;undefined&lt;/span&gt;

  &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;!&lt;/span&gt;&lt;span class="nx"&gt;ddl&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`Table not found: &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{table}`&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;columns&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;prepare&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`PRAGMA table_info(&lt;/span&gt;&lt;span class="se"&gt;\`\$&lt;/span&gt;&lt;span class="s2"&gt;{table}&lt;/span&gt;&lt;span class="se"&gt;\`&lt;/span&gt;&lt;span class="s2"&gt;)`&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;all&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;indexes&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;prepare&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`PRAGMA index_list(&lt;/span&gt;&lt;span class="se"&gt;\`\$&lt;/span&gt;&lt;span class="s2"&gt;{table}&lt;/span&gt;&lt;span class="se"&gt;\`&lt;/span&gt;&lt;span class="s2"&gt;)`&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;all&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;contents&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
      &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="nx"&gt;uri&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;mimeType&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;application/json&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;JSON&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stringify&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="na"&gt;ddl&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;ddl&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;sql&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;columns&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;indexes&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
      &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="p"&gt;],&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Defining Prompt Templates
&lt;/h2&gt;

&lt;p&gt;Prompts are reusable templates that surface inside Claude Code's slash-command picker. They can accept arguments and return pre-built message arrays.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// src/prompts.ts&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./index.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;ListPromptsRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;GetPromptRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/types.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;zod&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;ListPromptsRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
    &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;generate_migration&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Generate a SQL migration script to add a column to a table&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;arguments&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
        &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;table&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Target table name&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;required&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;column&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;New column definition (e.g. email TEXT NOT NULL DEFAULT &lt;/span&gt;&lt;span class="se"&gt;\'\'&lt;/span&gt;&lt;span class="s1"&gt;)&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;required&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt; &lt;span class="p"&gt;},&lt;/span&gt;
      &lt;span class="p"&gt;],&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;],&lt;/span&gt;
&lt;span class="p"&gt;}))&lt;/span&gt;

&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;GetPromptRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;arguments&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;promptArgs&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;params&lt;/span&gt;

  &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;name&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;generate_migration&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;schema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;object&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
      &lt;span class="na"&gt;table&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
      &lt;span class="na"&gt;column&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;string&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
    &lt;span class="p"&gt;})&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;table&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;column&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;schema&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;parse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;promptArgs&lt;/span&gt; &lt;span class="o"&gt;??&lt;/span&gt; &lt;span class="p"&gt;{})&lt;/span&gt;

    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;existingSchema&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;db&lt;/span&gt;
      &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;prepare&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`SELECT sql FROM sqlite_master WHERE type='table' AND name=?`&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
      &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;table&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;sql&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;|&lt;/span&gt; &lt;span class="kc"&gt;undefined&lt;/span&gt;

    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;existingSchema&lt;/span&gt;
      &lt;span class="p"&gt;?&lt;/span&gt; &lt;span class="s2"&gt;`Existing DDL:\n&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{existingSchema.sql}`&lt;/span&gt;
      &lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`Table '&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{table}' not found. Generate a CREATE TABLE + ALTER TABLE migration.`&lt;/span&gt;

    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;messages&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
        &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;role&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;user&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="kd"&gt;const&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;content&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;text&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="kd"&gt;const&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="na"&gt;text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`Generate a safe, idempotent SQLite migration to add '&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{column}' to '&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{table}'.

&lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{context}

Requirements:
- Use ALTER TABLE ... ADD COLUMN
- Include a rollback section (DROP COLUMN if SQLite version supports it)
- Add a comment with the date: &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{new Date().toISOString().split('T')[0]}
- Wrap in a transaction`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
      &lt;span class="p"&gt;],&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`Unknown prompt: &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{name}`&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Wiring Everything Together and Starting the Server
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// src/main.ts&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./tools.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./resources.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./prompts.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;server&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./index.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;StdioServerTransport&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/server/stdio.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;main&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;transport&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;StdioServerTransport&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
  &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;connect&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;transport&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="c1"&gt;// server is now listening on stdin/stdout&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="nf"&gt;main&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="k"&gt;catch&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;err&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;process&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;stderr&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;write&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`Fatal: &lt;/span&gt;&lt;span class="se"&gt;\$&lt;/span&gt;&lt;span class="s2"&gt;{err.message}\n`&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
  &lt;span class="nx"&gt;process&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;exit&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Registering with Claude Code
&lt;/h2&gt;

&lt;p&gt;Add the server to your &lt;code&gt;~/.claude.json&lt;/code&gt; (global) or project-level &lt;code&gt;.claude.json&lt;/code&gt;:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight json"&gt;&lt;code&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"mcpServers"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"db-introspection"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"command"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"node"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"args"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"dist/main.js"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"env"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
        &lt;/span&gt;&lt;span class="nl"&gt;"DB_PATH"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"/path/to/your/dev.sqlite"&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Then build and restart Claude Code:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;npx tsc
&lt;span class="c"&gt;# restart Claude Code — it spawns the server fresh each session&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Claude Code will now show your tools in its tool picker and your tables as readable resources.&lt;/p&gt;

&lt;h2&gt;
  
  
  Testing Without Claude Code
&lt;/h2&gt;

&lt;p&gt;Use the MCP inspector for quick iteration:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;npx @modelcontextprotocol/inspector node dist/main.js
&lt;span class="c"&gt;# Opens a browser UI at http://localhost:5173&lt;/span&gt;
&lt;span class="c"&gt;# Call tools, read resources, test prompts interactively&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;You can also write unit tests directly against your handler functions since they are plain async functions — no need to spin up the full server for logic tests.&lt;/p&gt;

&lt;h2&gt;
  
  
  Error Handling and Production Hardening
&lt;/h2&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="c1"&gt;// wrap every handler to catch unexpected errors&lt;/span&gt;
&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;safeHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
  &lt;span class="nx"&gt;handler&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;T&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt;
&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;T&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;try&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nf"&gt;handler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;req&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;catch &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;err&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;message&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;err&lt;/span&gt; &lt;span class="k"&gt;instanceof&lt;/span&gt; &lt;span class="nb"&gt;Error&lt;/span&gt; &lt;span class="p"&gt;?&lt;/span&gt; &lt;span class="nx"&gt;err&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;message&lt;/span&gt; &lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nc"&gt;String&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;err&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
      &lt;span class="c1"&gt;// MCP errors surface as structured error responses&lt;/span&gt;
      &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="nb"&gt;Object&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;assign&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;message&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;code&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt;&lt;span class="mi"&gt;32000&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  People Also Ask
&lt;/h2&gt;

&lt;h3&gt;
  
  
  What is the difference between MCP tools and resources?
&lt;/h3&gt;

&lt;p&gt;Tools are callable functions — Claude Code invokes them with arguments and gets a result back. Resources are read-only data endpoints — Claude reads them like files. Use tools for actions and computations; use resources for structured data that Claude should be able to browse or include as context.&lt;/p&gt;

&lt;h3&gt;
  
  
  Can I run an MCP server over HTTP instead of stdio?
&lt;/h3&gt;

&lt;p&gt;Yes. Replace &lt;code&gt;StdioServerTransport&lt;/code&gt; with &lt;code&gt;SSEServerTransport&lt;/code&gt; from &lt;code&gt;@modelcontextprotocol/sdk/server/sse.js&lt;/code&gt;. You set up an Express (or Hono) server, attach the transport to a route, and Claude Code connects via the server's URL instead of spawning a subprocess. This is required for remote or multi-user server deployments.&lt;/p&gt;

&lt;h3&gt;
  
  
  How do I keep sensitive credentials out of .claude.json?
&lt;/h3&gt;

&lt;h2&gt;
  
  
  Use the &lt;code&gt;env&lt;/code&gt; field in the server config to inject environment variables — pull values from your shell's existing env rather than hardcoding them. For team setups, use a secrets manager and inject at process startup. Never commit API keys or database credentials inside &lt;code&gt;.claude.json&lt;/code&gt;.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/claude-code-mcp-server-typescript-build-guide-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>mcpserver</category>
      <category>claudecode</category>
      <category>modelcontext</category>
      <category>buildmcp</category>
    </item>
    <item>
      <title>Alibaba Merges Qwen AI with Taobao: Agentic Shopping Hits 4 Billion Products</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Thu, 21 May 2026 15:30:14 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/alibaba-merges-qwen-ai-with-taobao-agentic-shopping-hits-4-billion-products-1nl7</link>
      <guid>https://forem.com/akaranjkar08/alibaba-merges-qwen-ai-with-taobao-agentic-shopping-hits-4-billion-products-1nl7</guid>
      <description>&lt;p&gt;&lt;strong&gt;Agentic shopping just went from a demo slide to the world's largest e-commerce platform.&lt;/strong&gt; On May 11, 2026, Reuters and multiple Asian tech outlets confirmed that Alibaba is integrating its Qwen AI app directly into Taobao and Tmall — its two largest consumer marketplaces — to launch what the company calls an "end-to-end agentic shopping" experience. A shopper opens Qwen, describes what they want, and the AI agent searches, compares sellers, runs virtual try-ons, monitors a 30-day price track, and completes checkout through Alipay. The only human step is the final payment confirmation. This is not a chatbot bolted onto a search bar. It is a full AI-native shopping loop running over four billion products, built by the same team behind one of the world's leading open-weight model families. Here is what is actually happening, how it works, and why it matters well beyond China.&lt;/p&gt;

&lt;h2&gt;
  
  
  What Is Qwen, and Why Does This Integration Matter
&lt;/h2&gt;

&lt;p&gt;Qwen is Alibaba's flagship AI model family, developed by the Tongyi Lab team. The Qwen 3 series — including the Qwen3-6-Max Preview that generated significant developer attention in early 2026 — has established itself as one of the most capable open-weight model families in the world, competitive with GPT-5.5 and Claude Opus 4.7 on specific reasoning and coding benchmarks. Alibaba releases most Qwen variants under Apache 2.0, making them freely deployable for commercial use. The Qwen app is the consumer product built on top of these models, roughly analogous to ChatGPT for OpenAI.&lt;/p&gt;

&lt;p&gt;What makes this integration remarkable is not that Alibaba built a capable AI — that was already known — but that it is directly wiring that AI into the infrastructure of a platform with more than one billion registered users and four billion product listings. The Qwen app gains access to the entire Taobao-Tmall catalogue plus a layer of Alibaba-built skills handling logistics, customer service, and after-sales workflows. It is the kind of vertical integration that is almost impossible to replicate from scratch: a frontier model, a consumer app, a payment layer (Alipay), and the world's largest inventory of goods, all owned by a single company.&lt;/p&gt;

&lt;h2&gt;
  
  
  The End-to-End Agentic Shopping Experience
&lt;/h2&gt;

&lt;p&gt;Here is what the experience looks like from a user's perspective, based on early documentation and reports from TechNode and Inside Retail Asia:&lt;/p&gt;

&lt;h3&gt;
  
  
  Step 1: Natural-Language Discovery
&lt;/h3&gt;

&lt;p&gt;The user opens Qwen and types or speaks a request: "Find me a lightweight running jacket under 400 yuan that fits a size M and ships before Friday." Qwen treats this as an agentic task, not a keyword query. It extracts intent, constraints, and time requirements, then issues structured queries against the Taobao-Tmall catalogue API.&lt;/p&gt;

&lt;h3&gt;
  
  
  Step 2: Multi-Seller Comparison
&lt;/h3&gt;

&lt;p&gt;Rather than returning a ranked list of ten options and leaving comparison to the user, the agent evaluates sellers on price, returns policy, delivery speed, and review sentiment, then surfaces a shortlist of two or three candidates with an explicit rationale. The output is structured enough to act on but transparent enough to override.&lt;/p&gt;

&lt;h3&gt;
  
  
  Step 3: Virtual Try-On
&lt;/h3&gt;

&lt;p&gt;For apparel, footwear, and accessories, Qwen can trigger a virtual try-on using a previously uploaded user photo or a real-time camera capture. The try-on layer is powered by Alibaba's existing Pailitao visual AI infrastructure, which has been running in Taobao since 2023, now surfaced through a conversational interface rather than a standalone feature buried in the app.&lt;/p&gt;

&lt;h3&gt;
  
  
  Step 4: 30-Day Price Tracking
&lt;/h3&gt;

&lt;p&gt;If the agent determines the item has been cheaper recently, it surfaces this and can schedule an automatic alert or a delayed purchase for when the price drops. This is a task that previously required a separate browser extension or deliberate effort from the user. In the agentic model, it is a default behavior the agent initiates without being asked.&lt;/p&gt;

&lt;h3&gt;
  
  
  Step 5: End-to-End Checkout
&lt;/h3&gt;

&lt;p&gt;The transaction completes through Alipay. The agent handles cart management, address selection, coupon application, and payment initiation. The user receives a single confirmation prompt before money moves. Alibaba's design explicitly keeps the human in the loop at the payment step — a deliberate trust boundary that reflects both regulatory caution and user research about how much autonomy consumers are comfortable delegating.&lt;/p&gt;

&lt;p&gt;Post-purchase, the agent can handle logistics queries ("where is my package?"), initiate return requests, and manage after-sales communications with the seller, all within the same Qwen interface.&lt;/p&gt;

&lt;h2&gt;
  
  
  The Scale Numbers That Make This Different
&lt;/h2&gt;

&lt;p&gt;The Alibaba-Qwen integration is not the first attempt at AI-powered shopping. Amazon has been running AI recommendation layers for years. Google Shopping has integrated Gemini for search refinement. Shopify launched agentic commerce features for merchants in early 2026. What makes this different is the scale at which it is launching.&lt;/p&gt;

&lt;p&gt;Qwen reached 300 million monthly active users across Taobao, Tmall, Alipay, and other Alibaba consumer surfaces by Q1 2026. During the Chinese New Year campaign — one of the heaviest e-commerce windows globally — approximately 140 million users logged their first AI-assisted shopping experience on Alibaba platforms. The platform being integrated into has more than four billion product listings across millions of active sellers. The payment layer (Alipay) processes over 100 million transactions per day at peak periods.&lt;/p&gt;

&lt;p&gt;Most AI shopping experiments run over hundreds of thousands of SKUs in controlled pilots. This one starts at four billion. It is the largest real-world test of agentic commerce that has ever been attempted, and the infrastructure it is running on has already been load-tested at a scale no Western competitor has matched.&lt;/p&gt;

&lt;h2&gt;
  
  
  How the Agentic Pipeline Works: The Technical Picture
&lt;/h2&gt;

&lt;p&gt;Alibaba has not released full technical documentation, but the architectural pattern described in developer briefings follows the agent-with-skills model that has become the dominant paradigm in 2026.&lt;/p&gt;

&lt;p&gt;Qwen acts as the orchestrator: it receives user intent, plans the sequence of subtasks, and calls specialized skills for each step. The skills are purpose-built API wrappers that have access to Taobao catalogue search, seller reputation scoring, visual search, try-on rendering, price history databases, Alipay payment APIs, and logistics tracking. This is the same architecture described in the &lt;a href="https://dev.to/blogs/microsoft-agent-365-enterprise-ai-control-plane-complete-guide-2026"&gt;Microsoft Agent 365 enterprise control plane&lt;/a&gt; and increasingly standard across production agentic systems in 2026.&lt;/p&gt;

&lt;p&gt;What Alibaba has built — and what makes it difficult to replicate quickly — is the skill layer. Each skill represents years of API development, data quality work, and operational hardening. The virtual try-on skill alone has been trained on hundreds of millions of product images and refined through billions of user interactions on Taobao. Connecting Qwen to these skills is valuable precisely because the skills themselves are mature.&lt;/p&gt;

&lt;p&gt;The shopping agent also uses Alibaba's internal memory infrastructure to personalize across sessions: it knows a user's size preferences, past purchases, and stated preferences, and uses these to narrow its initial search without requiring the user to repeat contextual details each time. This is the kind of persistent, cross-session state management that turns a capable demo into a genuinely useful product.&lt;/p&gt;

&lt;h2&gt;
  
  
  The Competitive Landscape: How This Changes the Game
&lt;/h2&gt;

&lt;p&gt;Alibaba's move comes in a week when agentic commerce is accelerating globally. Amazon has been integrating Alexa+ with its shopping infrastructure since late 2025, though its agentic capabilities remain more constrained on the discovery and comparison side. Google's Gemini integration into Google Shopping offers strong multimodal search but lacks the payment-through-completion that Alibaba is building. Shopify's agentic commerce features are merchant-facing — they help sellers configure AI-powered storefronts, but the buyer-side experience is still mediated through traditional checkout flows.&lt;/p&gt;

&lt;p&gt;The company that has come closest to Alibaba's approach is Perplexity, which launched a buy-side commerce agent in 2025 that can complete purchases through Shopify's checkout API. But Perplexity operates across a fragmented set of merchant integrations, while Alibaba operates within a single unified platform. The difference in coverage, data quality, and operational control is significant.&lt;/p&gt;

&lt;p&gt;For Western platforms, the question raised by Alibaba's move is whether the fragmented nature of Western e-commerce — spread across Amazon, Shopify merchants, Target, Walmart, and thousands of DTC sites — can ever support the kind of deeply integrated agentic experience that a single-platform operator can build. MCP (Model Context Protocol) has emerged as the interoperability standard that could allow an agent like ChatGPT or Claude to act across multiple retailer APIs using a common interface, as explored in the &lt;a href="https://dev.to/blogs/mcp-model-context-protocol-97-million-downloads-developer-guide-2026"&gt;MCP developer guide&lt;/a&gt;. But protocol-level integration is a decade behind proprietary integration in terms of capability and reliability.&lt;/p&gt;

&lt;h2&gt;
  
  
  What Developers and Commerce Teams Should Take Away
&lt;/h2&gt;

&lt;p&gt;If you are building shopping, commerce, or marketplace products in 2026, the Alibaba move signals several shifts worth acting on:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;&lt;p&gt;&lt;strong&gt;Agentic commerce is production, not R&amp;amp;D.&lt;/strong&gt; Alibaba is not running a lab experiment. It is deploying agentic shopping to 300 million users on the world's largest e-commerce platform. The pattern is validated at scale. Teams that are still treating AI shopping as a future capability are behind.&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;strong&gt;The trust boundary at payment is the right design call.&lt;/strong&gt; Alibaba explicitly keeps the human in the loop at payment confirmation. This is the correct answer to the "how much autonomy do you grant the agent?" question for high-stakes financial transactions. Build your agentic commerce flows with the same explicit confirmation step.&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;strong&gt;Skills quality matters more than model quality.&lt;/strong&gt; Qwen's model capabilities are impressive but not uniquely so. What makes the integration valuable is the quality of the skills it calls: the try-on renderer, the price history database, the seller reputation scorer. If you are building an agent for commerce, the investment in high-quality, reliable skill APIs is the actual competitive moat, not the LLM choice.&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;strong&gt;Memory and personalization are the compound interest of agentic products.&lt;/strong&gt; The persistent preference layer — knowing a user's size, style, and history — is what transforms a good first-use experience into a sticky daily habit. Build memory into agentic products from the beginning, not as a retrofit. The &lt;a href="https://dev.to/blogs/agent-memory-race-2026-mem0-zep-letta-mempalace"&gt;agent memory infrastructure landscape&lt;/a&gt; covers the current state of memory systems for production agents.&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;strong&gt;Vertical integration is a structural advantage, not just an efficiency gain.&lt;/strong&gt; Alibaba's ability to move from model to app to catalogue to payment in a single agentic loop is a function of controlling all four layers. Teams building on third-party APIs face coordination friction that Alibaba simply does not have. Where vertical integration is not possible, MCP-based standardization is the next-best solution.&lt;/p&gt;&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  The Broader Signal: AI Commerce Is Compressing the Purchase Funnel
&lt;/h2&gt;

&lt;p&gt;The traditional e-commerce purchase funnel — search, browse, compare, cart, checkout — was designed around human attention and choice architecture. Each step was a separate deliberate action. Agentic shopping collapses that funnel into a single natural-language statement, with the agent handling the intermediate steps autonomously.&lt;/p&gt;

&lt;p&gt;This compression has significant implications for how merchants think about discovery, conversion, and retention. If the agent makes the comparison decision, brand presentation in traditional search results becomes less important than the structured data signals the agent uses — reviews, returns policy, seller reputation score, shipping time commitments. Merchants who optimize for these machine-readable signals will outperform merchants who optimize for human visual attention.&lt;/p&gt;

&lt;p&gt;It also raises questions about what "shopping" means when the browsing is delegated. Part of shopping's value to consumers is not just acquisition — it is the experience of evaluation, discovery, and choice. How agentic platforms balance efficiency against the psychological value of the shopping experience will determine adoption rates among different consumer segments. Alibaba's choice to keep the try-on experience explicitly in the flow — rather than letting the agent skip it for speed — suggests they have thought carefully about this.&lt;/p&gt;

&lt;h2&gt;
  
  
  Conclusion
&lt;/h2&gt;

&lt;p&gt;Alibaba merging Qwen with Taobao is the most significant deployment of agentic commerce in history by any reasonable metric: model capability, scale, catalogue size, and payment integration. It validates the agentic shopping architecture at a level of real-world stress that no lab demonstration can match. And it sets a competitive benchmark that every e-commerce platform, AI company, and digital commerce team now has to respond to.&lt;/p&gt;

&lt;h2&gt;
  
  
  The pattern Alibaba is demonstrating — frontier model as orchestrator, domain-specific skills as capabilities, payment layer as the trust boundary, persistent memory as the compound advantage — is portable. You do not need four billion products to apply it. You need a clear understanding of which skills matter in your domain, the data quality to make those skills reliable, and the architectural discipline to keep humans in the loop at the moments that matter.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/alibaba-qwen-taobao-agentic-shopping-4-billion-products-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>alibabaqwen</category>
      <category>alibabaai</category>
      <category>qwenai</category>
      <category>agenticecommerce</category>
    </item>
    <item>
      <title>I Keep Hermes Agent's Self-Improvement OFF For the First 14 Days — Here's What Happens When I Don't</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Thu, 21 May 2026 15:24:37 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/i-keep-hermes-agents-self-improvement-off-for-the-first-14-days-heres-what-happens-when-i-dont-4agk</link>
      <guid>https://forem.com/akaranjkar08/i-keep-hermes-agents-self-improvement-off-for-the-first-14-days-heres-what-happens-when-i-dont-4agk</guid>
      <description>&lt;p&gt;&lt;strong&gt;I have published two articles praising Hermes Agent this week.&lt;/strong&gt; This one is different. Both of those articles are accurate — Hermes is genuinely excellent at self-directed skill acquisition, and the compounding effect of the memory system is real. But the self-improvement loop is too powerful to enable on day one. Three weeks ago I ignored my own rule on a fresh VPS deployment. By day 14, eleven auto-generated skills had silently degraded my agent's output quality across three production workflows. I lost an entire evening reverting to a clean state and hand-auditing every skill file. That evening is the reason this article exists.&lt;/p&gt;

&lt;p&gt;This is the contrarian Hermes Agent setup guide. The thesis is simple: &lt;strong&gt;disable &lt;code&gt;auto_create&lt;/code&gt; and &lt;code&gt;auto_refine&lt;/code&gt; for the first 14 days&lt;/strong&gt;, observe how the agent actually behaves on your real workload, hand-author your first generation of skills with intention, build the rollback infrastructure you will need later, and then enable self-improvement deliberately. The compounding still happens. It just compounds toward your actual workflow rather than toward the agent's confused first-week impressions of what you do.&lt;/p&gt;

&lt;h2&gt;
  
  
  The Default Is a Footgun
&lt;/h2&gt;

&lt;p&gt;Hermes Agent ships with self-improvement enabled. That is the right default for a demo environment, a low-stakes personal assistant, or a proof-of-concept. It is the wrong default for a production workload that touches customer data, deploys code, or handles anything with financial consequences. The default configuration assumes the agent will quickly learn what good looks like on your workload. It will learn something — but in the first week, what it observes is your onboarding confusion, your exploratory prompts, your experiments with workflow patterns you will ultimately discard. It encodes all of that as skills.&lt;/p&gt;

&lt;p&gt;There is no single flag that cleanly disables self-improvement in the default Hermes config. You have to set it explicitly. Here is the configuration I call "training wheels on" — the starting point for every new Hermes deployment I run:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# config.yaml — Hermes Agent "training wheels on" baseline&lt;/span&gt;
&lt;span class="c1"&gt;# Use this for the first 14 days on any new workload&lt;/span&gt;

&lt;span class="na"&gt;agent&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;hermes"&lt;/span&gt;
  &lt;span class="na"&gt;version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2.4"&lt;/span&gt;

&lt;span class="na"&gt;skills&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="c1"&gt;# Disable autonomous skill creation entirely&lt;/span&gt;
  &lt;span class="na"&gt;auto_create&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;

  &lt;span class="c1"&gt;# Disable autonomous skill refinement (agent cannot improve its own skills)&lt;/span&gt;
  &lt;span class="na"&gt;auto_refine&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;

  &lt;span class="c1"&gt;# Memory stays ON — you want observation data, just not autonomous action on it&lt;/span&gt;
  &lt;span class="na"&gt;memory_enabled&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="c1"&gt;# External dirs for read-only hand-written skills&lt;/span&gt;
  &lt;span class="c1"&gt;# The agent can USE these skills but cannot modify or create new ones&lt;/span&gt;
  &lt;span class="na"&gt;external_dirs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/home/hermes/skills/hand-authored"&lt;/span&gt;
      &lt;span class="na"&gt;mode&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;read-only"&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/home/hermes/skills/pinned"&lt;/span&gt;
      &lt;span class="na"&gt;mode&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;read-only"&lt;/span&gt;

  &lt;span class="c1"&gt;# Auto-created skills dir exists but nothing writes to it yet&lt;/span&gt;
  &lt;span class="na"&gt;managed_dir&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/home/hermes/skills/managed"&lt;/span&gt;
  &lt;span class="na"&gt;managed_dir_writable&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;

&lt;span class="na"&gt;memory&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;observation_log&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/home/hermes/logs/observations.jsonl"&lt;/span&gt;
  &lt;span class="na"&gt;session_summaries&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="na"&gt;cross_session_retention&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

&lt;span class="na"&gt;logging&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;level&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;info"&lt;/span&gt;
  &lt;span class="na"&gt;skill_invocations&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="na"&gt;skill_outcomes&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The key decisions in this config: memory stays on because you want the observation data accumulating, you just do not want the agent acting autonomously on those observations. The &lt;code&gt;external_dirs&lt;/code&gt; section gives the agent access to your hand-authored skills through a read-only mount so it can use them immediately, but it cannot modify them. The managed directory exists but &lt;code&gt;managed_dir_writable: false&lt;/code&gt; ensures nothing auto-generates there even if the agent tries.&lt;/p&gt;

&lt;h2&gt;
  
  
  Why "Delete Bad Skills Later" Doesn't Work
&lt;/h2&gt;

&lt;p&gt;The most common objection I hear to this approach is: "just let it run and prune the bad skills afterward." This sounds reasonable. It does not work, for three distinct reasons.&lt;/p&gt;

&lt;h3&gt;
  
  
  Reason 1: Self-Congratulation Bias
&lt;/h3&gt;

&lt;p&gt;The agent grades its own homework. When Hermes evaluates whether a skill it created is good, it uses the same reasoning model that created the skill in the first place. A skill that encodes a subtly wrong heuristic will generate outputs that look correct to the model that wrote the heuristic. The skill gets a high self-evaluation score. You have no external signal that something is wrong until the degradation shows up in actual output quality — which is a lagging indicator, often by days. By the time you notice the degradation, you have a week of accumulated sessions that all reinforced the bad skill.&lt;/p&gt;

&lt;h3&gt;
  
  
  Reason 2: The Skill Overwrite Problem
&lt;/h3&gt;

&lt;p&gt;If you do write hand-authored skills and enable auto-refinement simultaneously, the agent can and will degrade your hand-authored skills. The refinement loop identifies "opportunities for improvement" based on observed usage. If the agent observes that your hand-authored skill for "deploy to production" is invoked frequently but not always successfully (because some failures are user errors, not skill errors), it may "improve" the skill by adding conditionals that change the behavior for the common-failure cases. Your carefully tested skill is now different from what you wrote. The diff is subtle. You will not notice until a deployment fails in a new way.&lt;/p&gt;

&lt;h3&gt;
  
  
  Reason 3: The Accumulation Rate
&lt;/h3&gt;

&lt;p&gt;On a busy workload, Hermes generates approximately two to four skills per day on default settings. By day 14, you have 28 to 56 auto-generated skills. Auditing 50 skills is not a quick afternoon task — each skill requires you to understand what it encodes, test whether that encoding matches your actual intent, and decide whether to keep, modify, or delete it. In practice, most people do not do this audit. The skills accumulate. The agent's behavior drifts from what you intended, in small increments, over weeks. The drift is invisible until it is significant.&lt;/p&gt;

&lt;p&gt;The math on why starting clean is easier: zero skills to audit on day 14, versus 28–56. The 14-day observation period also gives you the data to write skills that reflect your real workflow, not your first-week exploration of the tool.&lt;/p&gt;

&lt;h2&gt;
  
  
  What I Do During the 14 Days
&lt;/h2&gt;

&lt;h3&gt;
  
  
  Day 1–3: Capture the Baseline
&lt;/h3&gt;

&lt;p&gt;The first three days are observation only. I run all the workflows I intend to automate through Hermes, treating the agent as a capable but un-optimized assistant. I take notes on what I am actually asking the agent to do, not what I thought I would ask it to do when I planned the deployment. These are always different.&lt;/p&gt;

&lt;p&gt;The observation log lives in a markdown file in my project directory, not in Hermes's memory system. I want a human-readable record I can query without routing through the agent:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight markdown"&gt;&lt;code&gt;&lt;span class="gh"&gt;# hermes-observation-log.md&lt;/span&gt;

&lt;span class="gu"&gt;## Day 1 — 2026-05-01&lt;/span&gt;

&lt;span class="gu"&gt;### Workflows run:&lt;/span&gt;
&lt;span class="p"&gt;-&lt;/span&gt; Deploy storefront to production (3x) — agent handled 2/3 correctly, 1 required manual intervention on Redis healthcheck
&lt;span class="p"&gt;-&lt;/span&gt; Generate and publish blog post (2x) — worked correctly both times, agent remembered WordPress API format from session 1 to session 2
&lt;span class="p"&gt;-&lt;/span&gt; Sync WooCommerce products from staging (1x) — FAILED: agent used wrong API version, needed correction

&lt;span class="gu"&gt;### Patterns noticed:&lt;/span&gt;
&lt;span class="p"&gt;-&lt;/span&gt; Agent repeatedly asks clarifying question about git branch before deploys — this should be a skill default
&lt;span class="p"&gt;-&lt;/span&gt; Agent does not know our VPS SSH key path — has to be prompted each session
&lt;span class="p"&gt;-&lt;/span&gt; Agent remembers API format within a session but not across sessions (memory not long enough?)

&lt;span class="gu"&gt;### Skills that would have helped:&lt;/span&gt;
&lt;span class="p"&gt;-&lt;/span&gt; skill/deploy-production: branch=main, ssh-key=/root/.ssh/deploy_key, healthcheck=redis+nextjs
&lt;span class="p"&gt;-&lt;/span&gt; skill/wordpress-publish: api-version=v2, base-url=wordpress-app:80, auth=env:WP_APP_PASSWORD

&lt;span class="gu"&gt;## Day 2 — 2026-05-02&lt;/span&gt;

&lt;span class="gu"&gt;### Workflows run:&lt;/span&gt;
...
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Three days of this log gives you something valuable: the real list of skills your deployment actually needs, derived from observation rather than upfront planning. The list is always shorter than you expected and more specific than any default skill set would produce.&lt;/p&gt;

&lt;h3&gt;
  
  
  Day 4–10: Hand-Author the First Generation
&lt;/h3&gt;

&lt;p&gt;With three days of observation data, I write skills manually. Every skill I write follows a fixed template with YAML frontmatter, a procedure section, a pitfalls section, and a verification block. The verification block is non-negotiable — it is what makes skill quality objectively measurable rather than subjective:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="nn"&gt;---&lt;/span&gt;
&lt;span class="na"&gt;skill_id&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;deploy-production&lt;/span&gt;
&lt;span class="na"&gt;version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;1.0.0&lt;/span&gt;
&lt;span class="na"&gt;author&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anup&lt;/span&gt;
&lt;span class="na"&gt;created&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;2026-05-04&lt;/span&gt;
&lt;span class="na"&gt;pinned&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
&lt;span class="na"&gt;no_auto_refine&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
&lt;span class="na"&gt;tags&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;deploy&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;production&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;vps&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;docker&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
&lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;&amp;gt;"&lt;/span&gt;
  &lt;span class="s"&gt;Deploys the storefront to the production VPS via SSH.&lt;/span&gt;
  &lt;span class="s"&gt;Handles Redis healthcheck, Docker Compose restart, and&lt;/span&gt;
  &lt;span class="s"&gt;liveness verification.&lt;/span&gt;
&lt;span class="nn"&gt;---&lt;/span&gt;

&lt;span class="c1"&gt;# skill: deploy-production&lt;/span&gt;

&lt;span class="c1"&gt;## Purpose&lt;/span&gt;

&lt;span class="s"&gt;Deploy the storefront Next.js application to the production VPS.&lt;/span&gt;
&lt;span class="s"&gt;Use this skill whenever the user asks to deploy, push to production,&lt;/span&gt;
&lt;span class="s"&gt;or ship changes live.&lt;/span&gt;

&lt;span class="c1"&gt;## Prerequisites&lt;/span&gt;

&lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;SSH key at /root/.ssh/deploy_key must exist&lt;/span&gt;
&lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;Environment variable VPS_HOST must be set&lt;/span&gt;
&lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;User must confirm they are on the correct git branch before proceeding&lt;/span&gt;

&lt;span class="c1"&gt;## Procedure&lt;/span&gt;

&lt;span class="na"&gt;1. Confirm git branch&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;

   &lt;span class="s"&gt;git branch --show-current&lt;/span&gt;

   &lt;span class="s"&gt;Expected&lt;/span&gt;&lt;span class="err"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;main". If not "main", STOP and ask user to confirm.&lt;/span&gt;

&lt;span class="na"&gt;2. Confirm working tree is clean&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;

   &lt;span class="s"&gt;git status --short&lt;/span&gt;

   &lt;span class="s"&gt;Expected&lt;/span&gt;&lt;span class="err"&gt;:&lt;/span&gt; &lt;span class="s"&gt;empty output. If not empty, STOP and ask user whether to stash or commit.&lt;/span&gt;

&lt;span class="na"&gt;3. Push to remote&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;

   &lt;span class="s"&gt;git push origin main&lt;/span&gt;

&lt;span class="na"&gt;4. Wait for GitHub Actions to complete (poll gh run list until conclusion=success)&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;

   &lt;span class="s"&gt;gh run list --branch main --limit 1 --json conclusion,status&lt;/span&gt;

   &lt;span class="s"&gt;Poll every 30 seconds. Timeout after 10 minutes.&lt;/span&gt;

&lt;span class="na"&gt;5. Verify liveness after deploy&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;

   &lt;span class="s"&gt;curl -s -o /dev/null -w "%{http_code}" https://wowhow.cloud/&lt;/span&gt;

   &lt;span class="s"&gt;Expected&lt;/span&gt;&lt;span class="err"&gt;:&lt;/span&gt; &lt;span class="s"&gt;200. If not 200, trigger rollback procedure.&lt;/span&gt;

&lt;span class="c1"&gt;## Pitfalls&lt;/span&gt;

&lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;Do NOT deploy if Redis healthcheck fails before deploy — the deploy will not fix it&lt;/span&gt;
&lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;Do NOT interpret a 301 redirect as a success — check for 200 from the final URL&lt;/span&gt;
&lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;GitHub Actions concurrency means only one deploy runs at a time — do not push again while a run is active&lt;/span&gt;
&lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;If conclusion=cancelled, the next queued push will deploy — wait, do not push again&lt;/span&gt;

&lt;span class="c1"&gt;## Verification&lt;/span&gt;

&lt;span class="s"&gt;After running this skill, the following must all be &lt;/span&gt;&lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="err"&gt;:&lt;/span&gt;

&lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;curl https://wowhow.cloud/ returns HTTP &lt;/span&gt;&lt;span class="m"&gt;200&lt;/span&gt;
&lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;gh run list --limit 1 shows conclusion=success&lt;/span&gt;
&lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;No active deploy lock at /tmp/wowhow-deploy.lock on VPS&lt;/span&gt;

&lt;span class="c1"&gt;## Rollback&lt;/span&gt;

&lt;span class="s"&gt;If verification fails, run&lt;/span&gt;&lt;span class="err"&gt;:&lt;/span&gt; &lt;span class="s"&gt;skill/rollback-production&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;This template takes longer to write than an auto-generated skill. That is the point. The effort of writing it forces you to think through edge cases, failure modes, and verification criteria that auto-generation skips. The resulting skill is dramatically more reliable in production.&lt;/p&gt;

&lt;p&gt;During days 4–10, I typically write between five and twelve skills, covering the core workflows identified in the observation log. Each skill goes into &lt;code&gt;/home/hermes/skills/hand-authored/&lt;/code&gt; where it is accessible to the agent but protected from modification by the read-only mount in the config.&lt;/p&gt;

&lt;h3&gt;
  
  
  Day 11–14: Build Rollback Infrastructure
&lt;/h3&gt;

&lt;p&gt;Before enabling self-improvement, I need to be able to revert to a known-good state without manual effort. The rollback infrastructure has three components: git tracking of the skills directory, a wrapper script that enforces the git commit on every skill write, and a restore command.&lt;/p&gt;

&lt;p&gt;Initialize git in the skills directory:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="c"&gt;# Initialize git tracking for the skills directory&lt;/span&gt;
&lt;span class="nb"&gt;cd&lt;/span&gt; /home/hermes/skills
git init
git add hand-authored/ pinned/
git commit &lt;span class="nt"&gt;-m&lt;/span&gt; &lt;span class="s2"&gt;"day-14 baseline: hand-authored skills before enabling auto_create"&lt;/span&gt;

&lt;span class="c"&gt;# Tag the baseline explicitly&lt;/span&gt;
git tag baseline-day14
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The wrapper script is the key piece. When I enable auto-creation on day 15, I want every auto-generated skill to be committed to git immediately when Hermes writes it. This gives me a complete audit trail and a one-command rollback path. Here is the full wrapper script I use:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="c"&gt;#!/usr/bin/env bash&lt;/span&gt;
&lt;span class="c"&gt;# skill-write-with-audit.sh&lt;/span&gt;
&lt;span class="c"&gt;# Wrap every skill write operation with a git commit.&lt;/span&gt;
&lt;span class="c"&gt;# Usage: skill-write-with-audit.sh  &lt;/span&gt;
&lt;span class="c"&gt;#&lt;/span&gt;
&lt;span class="c"&gt;# Hermes Agent calls this script instead of writing skill files directly.&lt;/span&gt;
&lt;span class="c"&gt;# Configure in config.yaml: skills.write_hook: "/home/hermes/bin/skill-write-with-audit.sh"&lt;/span&gt;

&lt;span class="nb"&gt;set&lt;/span&gt; &lt;span class="nt"&gt;-euo&lt;/span&gt; pipefail

&lt;span class="nv"&gt;SKILL_PATH&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;1&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;
&lt;span class="nv"&gt;CONTENT_FILE&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;2&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;
&lt;span class="nv"&gt;SKILLS_ROOT&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="s2"&gt;"/home/hermes/skills"&lt;/span&gt;
&lt;span class="nv"&gt;LOG_FILE&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="s2"&gt;"/home/hermes/logs/skill-audit.log"&lt;/span&gt;
&lt;span class="nv"&gt;TIMESTAMP&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="si"&gt;$(&lt;/span&gt;&lt;span class="nb"&gt;date&lt;/span&gt; &lt;span class="nt"&gt;-u&lt;/span&gt; +&lt;span class="s2"&gt;"%Y-%m-%dT%H:%M:%SZ"&lt;/span&gt;&lt;span class="si"&gt;)&lt;/span&gt;

&lt;span class="c"&gt;# Validate inputs&lt;/span&gt;
&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;[[&lt;/span&gt; &lt;span class="nt"&gt;-z&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="nt"&gt;-z&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;CONTENT_FILE&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt; &lt;span class="o"&gt;]]&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt; &lt;span class="k"&gt;then
  &lt;/span&gt;&lt;span class="nb"&gt;echo&lt;/span&gt; &lt;span class="s2"&gt;"[&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;TIMESTAMP&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;] ERROR: Missing arguments. Usage: &lt;/span&gt;&lt;span class="nv"&gt;$0&lt;/span&gt;&lt;span class="s2"&gt;  "&lt;/span&gt; | &lt;span class="nb"&gt;tee&lt;/span&gt; &lt;span class="nt"&gt;-a&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;LOG_FILE&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;
  &lt;span class="nb"&gt;exit &lt;/span&gt;1
&lt;span class="k"&gt;fi&lt;/span&gt;

&lt;span class="c"&gt;# Resolve absolute path&lt;/span&gt;
&lt;span class="nv"&gt;ABS_SKILL_PATH&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;SKILLS_ROOT&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;/&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;

&lt;span class="c"&gt;# Ensure the target directory exists&lt;/span&gt;
&lt;span class="nb"&gt;mkdir&lt;/span&gt; &lt;span class="nt"&gt;-p&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="si"&gt;$(&lt;/span&gt;&lt;span class="nb"&gt;dirname&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;ABS_SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="si"&gt;)&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;

&lt;span class="c"&gt;# Check if this is an update to an existing skill&lt;/span&gt;
&lt;span class="nv"&gt;IS_UPDATE&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="nb"&gt;false
&lt;/span&gt;&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;[[&lt;/span&gt; &lt;span class="nt"&gt;-f&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;ABS_SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt; &lt;span class="o"&gt;]]&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt; &lt;span class="k"&gt;then
  &lt;/span&gt;&lt;span class="nv"&gt;IS_UPDATE&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="nb"&gt;true&lt;/span&gt;
  &lt;span class="c"&gt;# Capture the pre-modification state for the log&lt;/span&gt;
  &lt;span class="nv"&gt;PREV_VERSION&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="si"&gt;$(&lt;/span&gt;&lt;span class="nb"&gt;grep&lt;/span&gt; &lt;span class="nt"&gt;-m1&lt;/span&gt; &lt;span class="s2"&gt;"^version:"&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;ABS_SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="nb"&gt;echo&lt;/span&gt; &lt;span class="s2"&gt;"unknown"&lt;/span&gt;&lt;span class="si"&gt;)&lt;/span&gt;
&lt;span class="k"&gt;fi&lt;/span&gt;

&lt;span class="c"&gt;# Write the skill file&lt;/span&gt;
&lt;span class="nb"&gt;cp&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;CONTENT_FILE&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;ABS_SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;

&lt;span class="c"&gt;# Extract metadata from the written file&lt;/span&gt;
&lt;span class="nv"&gt;SKILL_ID&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="si"&gt;$(&lt;/span&gt;&lt;span class="nb"&gt;grep&lt;/span&gt; &lt;span class="nt"&gt;-m1&lt;/span&gt; &lt;span class="s2"&gt;"^skill_id:"&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;ABS_SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt; | &lt;span class="nb"&gt;awk&lt;/span&gt; &lt;span class="s1"&gt;'{print $2}'&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="nb"&gt;echo&lt;/span&gt; &lt;span class="s2"&gt;"unknown"&lt;/span&gt;&lt;span class="si"&gt;)&lt;/span&gt;
&lt;span class="nv"&gt;NEW_VERSION&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="si"&gt;$(&lt;/span&gt;&lt;span class="nb"&gt;grep&lt;/span&gt; &lt;span class="nt"&gt;-m1&lt;/span&gt; &lt;span class="s2"&gt;"^version:"&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;ABS_SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt; | &lt;span class="nb"&gt;awk&lt;/span&gt; &lt;span class="s1"&gt;'{print $2}'&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="nb"&gt;echo&lt;/span&gt; &lt;span class="s2"&gt;"unknown"&lt;/span&gt;&lt;span class="si"&gt;)&lt;/span&gt;

&lt;span class="c"&gt;# Commit to git&lt;/span&gt;
&lt;span class="nb"&gt;cd&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;SKILLS_ROOT&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;

&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="o"&gt;[[&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;IS_UPDATE&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="s2"&gt;"true"&lt;/span&gt; &lt;span class="o"&gt;]]&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt; &lt;span class="k"&gt;then
  &lt;/span&gt;&lt;span class="nv"&gt;COMMIT_MSG&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="s2"&gt;"auto-refine: &lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;SKILL_ID&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; &lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;PREV_VERSION&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; to &lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;NEW_VERSION&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; [&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;TIMESTAMP&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;]"&lt;/span&gt;
&lt;span class="k"&gt;else
  &lt;/span&gt;&lt;span class="nv"&gt;COMMIT_MSG&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="s2"&gt;"auto-create: &lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;SKILL_ID&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; v&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;NEW_VERSION&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; [&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;TIMESTAMP&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;]"&lt;/span&gt;
&lt;span class="k"&gt;fi

&lt;/span&gt;git add &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;ABS_SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;
git commit &lt;span class="nt"&gt;-m&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;COMMIT_MSG&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;
&lt;span class="nv"&gt;COMMIT_HASH&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="si"&gt;$(&lt;/span&gt;git rev-parse &lt;span class="nt"&gt;--short&lt;/span&gt; HEAD&lt;span class="si"&gt;)&lt;/span&gt;

&lt;span class="c"&gt;# Log the operation&lt;/span&gt;
&lt;span class="nb"&gt;echo&lt;/span&gt; &lt;span class="s2"&gt;"[&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;TIMESTAMP&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;] skill_write | id=&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;SKILL_ID&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; | path=&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; | version=&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;NEW_VERSION&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; | update=&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;IS_UPDATE&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; | commit=&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;COMMIT_HASH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt; | &lt;span class="nb"&gt;tee&lt;/span&gt; &lt;span class="nt"&gt;-a&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;LOG_FILE&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;

&lt;span class="nb"&gt;echo&lt;/span&gt; &lt;span class="s2"&gt;"OK: &lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;SKILL_PATH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; written and committed as &lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="nv"&gt;COMMIT_HASH&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Make it executable and configure Hermes to use it:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="nb"&gt;chmod&lt;/span&gt; +x /home/hermes/bin/skill-write-with-audit.sh

&lt;span class="c"&gt;# Add to config.yaml under the skills section:&lt;/span&gt;
&lt;span class="c"&gt;# skills:&lt;/span&gt;
&lt;span class="c"&gt;#   write_hook: "/home/hermes/bin/skill-write-with-audit.sh"&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;With this hook in place, every auto-generated skill is a git commit. Rolling back to the day-14 baseline is a single command:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="c"&gt;# Roll back all auto-generated skills to the day-14 baseline&lt;/span&gt;
&lt;span class="nb"&gt;cd&lt;/span&gt; /home/hermes/skills
git checkout baseline-day14 &lt;span class="nt"&gt;--&lt;/span&gt; managed/

&lt;span class="c"&gt;# Verify the rollback&lt;/span&gt;
git log &lt;span class="nt"&gt;--oneline&lt;/span&gt; &lt;span class="nt"&gt;-5&lt;/span&gt;
git diff baseline-day14 HEAD &lt;span class="nt"&gt;--&lt;/span&gt; managed/ | &lt;span class="nb"&gt;head&lt;/span&gt; &lt;span class="nt"&gt;-50&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  End of Day 14: The Activation Ritual
&lt;/h3&gt;

&lt;p&gt;Before flipping the switch, I run through a fixed checklist. Skipping any item means waiting another 24 hours:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight markdown"&gt;&lt;code&gt;&lt;span class="gh"&gt;# Hermes Agent Day-14 Activation Checklist&lt;/span&gt;
&lt;span class="gh"&gt;# Complete ALL items before enabling auto_create / auto_refine&lt;/span&gt;
&lt;span class="p"&gt;
-&lt;/span&gt; [ ] Observation log has at least 3 days of workflow data
&lt;span class="p"&gt;-&lt;/span&gt; [ ] At least 5 hand-authored skills written and tested manually
&lt;span class="p"&gt;-&lt;/span&gt; [ ] Each hand-authored skill has a verification block with specific, testable criteria
&lt;span class="p"&gt;-&lt;/span&gt; [ ] Skills directory is a git repo with baseline-day14 tag
&lt;span class="p"&gt;-&lt;/span&gt; [ ] skill-write-with-audit.sh is executable and tested (run it manually once)
&lt;span class="p"&gt;-&lt;/span&gt; [ ] Rollback command tested: git checkout baseline-day14 -- managed/ runs clean
&lt;span class="p"&gt;-&lt;/span&gt; [ ] Audit log path is writable: touch /home/hermes/logs/skill-audit.log succeeds
&lt;span class="p"&gt;-&lt;/span&gt; [ ] Config backup taken: cp config.yaml config.yaml.day14-backup
&lt;span class="p"&gt;-&lt;/span&gt; [ ] Team notified that self-improvement is being enabled (if applicable)
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;When all items are checked, I update the config to enable auto-creation with conservative guardrails:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# config.yaml — Day 15+ configuration&lt;/span&gt;
&lt;span class="c1"&gt;# Self-improvement enabled with production guardrails&lt;/span&gt;

&lt;span class="na"&gt;skills&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;auto_create&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="na"&gt;auto_refine&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="c1"&gt;# Conservative creation threshold — agent must observe the same&lt;/span&gt;
  &lt;span class="c1"&gt;# pattern at least 5 times before creating a skill for it&lt;/span&gt;
  &lt;span class="na"&gt;auto_create_threshold&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;5&lt;/span&gt;

  &lt;span class="c1"&gt;# Refinement requires a meaningful quality delta, not marginal improvement&lt;/span&gt;
  &lt;span class="na"&gt;auto_refine_min_improvement&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0.15&lt;/span&gt;

  &lt;span class="c1"&gt;# Maximum skills auto-created per day — prevents accumulation explosions&lt;/span&gt;
  &lt;span class="na"&gt;auto_create_daily_limit&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;2&lt;/span&gt;

  &lt;span class="c1"&gt;# Write hook — every skill write goes through the audit wrapper&lt;/span&gt;
  &lt;span class="na"&gt;write_hook&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/home/hermes/bin/skill-write-with-audit.sh"&lt;/span&gt;

  &lt;span class="c1"&gt;# Hand-authored skills remain read-only even now&lt;/span&gt;
  &lt;span class="na"&gt;external_dirs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/home/hermes/skills/hand-authored"&lt;/span&gt;
      &lt;span class="na"&gt;mode&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;read-only"&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/home/hermes/skills/pinned"&lt;/span&gt;
      &lt;span class="na"&gt;mode&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;read-only"&lt;/span&gt;

  &lt;span class="na"&gt;managed_dir&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/home/hermes/skills/managed"&lt;/span&gt;
  &lt;span class="na"&gt;managed_dir_writable&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;auto_create_threshold: 5&lt;/code&gt; and &lt;code&gt;auto_create_daily_limit: 2&lt;/code&gt; are the two guardrails I consider non-negotiable even after enabling self-improvement. The threshold prevents the agent from creating skills based on one-off requests. The daily limit means that even in the worst case, you have at most two new things to audit per day rather than four or more.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pinning Critical Skills
&lt;/h2&gt;

&lt;p&gt;Some skills must never be deleted, archived, or modified by the self-improvement loop, regardless of how the agent evaluates them. Production deployments, security-related workflows, and the audit wrapper itself all belong in this category. Hermes has a pin mechanism for exactly this purpose:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="c"&gt;# Pin a skill so the self-improvement loop never touches it&lt;/span&gt;
hermes curator pin skill/deploy-production
hermes curator pin skill/rollback-production
hermes curator pin skill/security-review-checklist

&lt;span class="c"&gt;# Verify pinned skills&lt;/span&gt;
hermes curator list &lt;span class="nt"&gt;--pinned&lt;/span&gt;

&lt;span class="c"&gt;# Output:&lt;/span&gt;
&lt;span class="c"&gt;# PINNED SKILLS&lt;/span&gt;
&lt;span class="c"&gt;# -------------&lt;/span&gt;
&lt;span class="c"&gt;# skill/deploy-production      v1.0.0   pinned: 2026-05-15&lt;/span&gt;
&lt;span class="c"&gt;# skill/rollback-production    v1.0.0   pinned: 2026-05-15&lt;/span&gt;
&lt;span class="c"&gt;# skill/security-review-checklist  v1.2.0   pinned: 2026-05-15&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Pinned skills also live in &lt;code&gt;/home/hermes/skills/pinned/&lt;/code&gt; which is mounted read-only even in the day-15+ configuration above. The git tracking still applies — if you manually update a pinned skill, the audit wrapper logs the change — but the self-improvement loop cannot touch them.&lt;/p&gt;

&lt;p&gt;The YAML frontmatter for a pinned skill looks like this:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="nn"&gt;---&lt;/span&gt;
&lt;span class="na"&gt;skill_id&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;deploy-production&lt;/span&gt;
&lt;span class="na"&gt;version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;1.0.0&lt;/span&gt;
&lt;span class="na"&gt;author&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anup&lt;/span&gt;
&lt;span class="na"&gt;created&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;2026-05-04&lt;/span&gt;
&lt;span class="na"&gt;pinned&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
&lt;span class="na"&gt;no_auto_refine&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
&lt;span class="na"&gt;tags&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;deploy&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;production&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;pinned&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
&lt;span class="nn"&gt;---&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Setting both &lt;code&gt;pinned: true&lt;/code&gt; and &lt;code&gt;no_auto_refine: true&lt;/code&gt; in the frontmatter creates a belt-and-suspenders guarantee. The &lt;code&gt;pinned&lt;/code&gt; flag is enforced by the curator. The &lt;code&gt;no_auto_refine&lt;/code&gt; flag is enforced by the self-improvement loop itself. Either one alone is sufficient; both together ensure the skill survives any config change or curator state reset.&lt;/p&gt;

&lt;h2&gt;
  
  
  Four Workflows That Should Never Be on Auto
&lt;/h2&gt;

&lt;p&gt;Even after day 14, there are categories of workflow where I permanently keep auto-refinement disabled. These are set with the &lt;code&gt;no_auto_refine&lt;/code&gt; frontmatter flag, not by the global config, so they stay protected regardless of what the global &lt;code&gt;auto_refine&lt;/code&gt; setting is.&lt;/p&gt;

&lt;h3&gt;
  
  
  1. Production Deployments
&lt;/h3&gt;

&lt;p&gt;Any skill that touches the production deployment pipeline gets &lt;code&gt;no_auto_refine: true&lt;/code&gt; and &lt;code&gt;pinned: true&lt;/code&gt;. The reasoning is simple: a deployment skill that has been tested and is working correctly should not be modified by an automated process. The cost of a bad deployment is high enough that human review of every change to the deploy skill is worth the overhead.&lt;/p&gt;

&lt;h3&gt;
  
  
  2. Security Reviews and Audit Checklists
&lt;/h3&gt;

&lt;p&gt;Security review skills encode decisions made with deliberate human judgment about what constitutes an acceptable risk on this specific workload. An automated refinement process does not have the context to make those judgments. More importantly, a subtly weakened security review skill — one that drops a check that seems redundant based on recent session patterns — is exactly the kind of silent degradation that causes real incidents.&lt;/p&gt;

&lt;h3&gt;
  
  
  3. Customer-Facing Workflows
&lt;/h3&gt;

&lt;p&gt;Any skill that generates content, sends communications, or takes actions visible to customers gets &lt;code&gt;no_auto_refine: true&lt;/code&gt;. The agent's self-evaluation of output quality is based on patterns in past sessions. Customer-facing quality has dimensions the agent cannot observe: tone consistency with your brand, regulatory compliance, and the implicit expectations of your specific customer base. Automated refinement optimizes for what the agent can measure, which is not the same thing as customer quality.&lt;/p&gt;

&lt;h3&gt;
  
  
  4. The Audit Wrapper Itself
&lt;/h3&gt;

&lt;p&gt;The &lt;code&gt;skill-write-with-audit.sh&lt;/code&gt; wrapper must never be modified by any automated process. This is the ouroboros risk: if the self-improvement loop can modify the mechanism by which skill modifications are logged, the audit trail becomes unreliable. The wrapper lives outside the skills directory entirely, owned by root, and is never referenced in any Hermes skill file as a dependency.&lt;/p&gt;

&lt;p&gt;The config block that enforces these permanent exceptions at the skill level rather than globally:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# These skills have auto-refinement permanently disabled&lt;/span&gt;
&lt;span class="c1"&gt;# regardless of the global auto_refine setting.&lt;/span&gt;
&lt;span class="c1"&gt;# Set in each skill's YAML frontmatter:&lt;/span&gt;

&lt;span class="c1"&gt;# skill/deploy-production&lt;/span&gt;
&lt;span class="na"&gt;no_auto_refine&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
&lt;span class="na"&gt;pinned&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

&lt;span class="c1"&gt;# skill/rollback-production&lt;/span&gt;
&lt;span class="na"&gt;no_auto_refine&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
&lt;span class="na"&gt;pinned&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

&lt;span class="c1"&gt;# skill/security-review-checklist&lt;/span&gt;
&lt;span class="na"&gt;no_auto_refine&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
&lt;span class="na"&gt;pinned&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

&lt;span class="c1"&gt;# skill/customer-email-template&lt;/span&gt;
&lt;span class="na"&gt;no_auto_refine&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

&lt;span class="c1"&gt;# skill/wordpress-publish&lt;/span&gt;
&lt;span class="na"&gt;no_auto_refine&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  The Honest Other Side
&lt;/h2&gt;

&lt;p&gt;It is fair to push back on this approach. If you are running Hermes on a low-stakes workload — personal productivity, research summarization, drafting non-critical content — the 14-day observation period is probably unnecessary friction. The default self-improvement settings will produce a reasonably good agent within a week, and the cost of a bad auto-generated skill is low enough that you can simply delete it when you notice the problem.&lt;/p&gt;

&lt;p&gt;The rule is specifically for production workloads, customer-facing systems, and workflows where a subtle degradation in agent behavior costs real money or damages real relationships before you catch it. If your Hermes deployment does not touch any of those categories, you can safely ignore this article and turn on self-improvement on day one.&lt;/p&gt;

&lt;p&gt;I also want to be honest about the overhead. The 14-day observation period, the hand-authored skills, the git infrastructure, and the rollback tooling together represent roughly eight to twelve hours of work that a default deployment skips. That is a real cost. It pays back on production workloads because the alternative — debugging a degraded agent while production workflows are impaired — costs more. On a side project, the math probably does not work out in the same direction.&lt;/p&gt;

&lt;p&gt;The clearest decision heuristic I have found: &lt;strong&gt;if you would run a staging environment and a rollback procedure for code changes to this workload, run them for your agent skills too.&lt;/strong&gt; If you would not, default settings are probably fine.&lt;/p&gt;

&lt;h2&gt;
  
  
  Closing
&lt;/h2&gt;

&lt;p&gt;Self-improvement is too powerful to enable on a workload you do not yet understand. The first 14 days of any new Hermes deployment are a learning period for you, not just for the agent. You are learning what the agent actually does on your real tasks, what the friction points are, where the agent excels without any skills at all, and where the gaps are that hand-authored skills can fill. Blocking self-improvement during that period is not about distrust of the agent. It is about having the data you need to make the self-improvement loop produce good outcomes.&lt;/p&gt;

&lt;p&gt;When I enable self-improvement on day 15 with the conservative guardrails in place, the compounding still happens. It just compounds toward my real workflow rather than toward my first-week confusion. The difference in output quality after 30 more days is significant. The skills the agent generates are coherent with the hand-authored baseline, targeted at actual patterns rather than exploratory noise, and limited in accumulation rate so the audit burden stays manageable.&lt;/p&gt;

&lt;p&gt;The evening I spent reverting eleven bad auto-generated skills from my last fresh deployment convinced me to never skip the observation period again. It is a better use of that time than debugging a degraded agent on a live workload.&lt;/p&gt;

&lt;h2&gt;
  
  
  If you found this useful, the two Hermes Agent articles I referenced at the start cover the positive case — what self-improvement looks like when it is working correctly, and the architecture of the skill system that makes it possible. This article is the prerequisite, not the replacement.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/hermes-agent-self-improvement-off-14-days-skill-drift-production-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>hermesagent</category>
      <category>hermesskill</category>
      <category>hermesauto</category>
      <category>agents</category>
    </item>
    <item>
      <title>I Built the Hermes + Claude Code Dual-Stack: Orchestrator Meets Coder — Here's the Full Architecture</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Thu, 21 May 2026 15:24:32 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/i-built-the-hermes-claude-code-dual-stack-orchestrator-meets-coder-heres-the-full-architecture-228a</link>
      <guid>https://forem.com/akaranjkar08/i-built-the-hermes-claude-code-dual-stack-orchestrator-meets-coder-heres-the-full-architecture-228a</guid>
      <description>&lt;p&gt;&lt;strong&gt;The framing showed up in a few places at the same time.&lt;/strong&gt; A thread on Indie Hackers, a post on browseract, some Discord chatter: Hermes Agent as the orchestrator, Claude Code as the coder. Two agents, one stack, specialization instead of generalization. The framing made sense to me immediately. What nobody published was a working architecture — actual config files, the MCP bridge that connects them, and the failure modes you hit when you try to run this in production.&lt;/p&gt;

&lt;p&gt;I spent two weeks building and debugging this dual-stack setup. I run it daily now. This is the complete architecture: VPS side, local side, the MCP bridge between them, six production patterns, and an honest accounting of what broke and what stuck.&lt;/p&gt;

&lt;h2&gt;
  
  
  Why Dual-Stack at All
&lt;/h2&gt;

&lt;p&gt;The single-agent problem is real. I was running Claude Code as my primary agent for everything — code generation, git operations, GitHub issue management, cron-like scheduling via shell scripts. It works, but there are gaps. Claude Code is exceptional at code generation, file editing, and TypeScript/React tasks. It is not designed for persistent messaging, Telegram integration, or scheduling. Every time I wanted a notification when a task completed, I had to wire something up manually. Every time I wanted to trigger a code task from my phone, I was doing gymnastics.&lt;/p&gt;

&lt;p&gt;Hermes is the inverse. It is excellent at persistent orchestration — running tasks on a schedule, consuming messages from Telegram or Discord, maintaining memory across sessions, coordinating multi-step workflows that span minutes or hours. It is not a specialized coder. When Hermes writes code, it is using a general-purpose model for a task where Claude Code has been specifically optimized.&lt;/p&gt;

&lt;p&gt;The dual-stack argument is simple: let each agent do what it does best and bridge them. The complexity cost is real — two agent runtimes, a bidirectional MCP bridge, synchronized config — but the capability gain justifies it if you are building in public or running a product that needs both coding and operational automation.&lt;/p&gt;

&lt;h2&gt;
  
  
  Architecture Overview
&lt;/h2&gt;

&lt;p&gt;The stack has three components:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;&lt;p&gt;&lt;strong&gt;Hermes on VPS&lt;/strong&gt; — always-on, receives Telegram messages, runs cron jobs, maintains memory, and dispatches work&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;strong&gt;Claude Code on local machine&lt;/strong&gt; — has full codebase access, IDE integration, runs tests, writes and edits files&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;strong&gt;MCP bridge&lt;/strong&gt; — bidirectional: Claude Code calls Hermes tools, Hermes calls Claude Code tools&lt;/p&gt;&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;The key architectural decision is that Hermes runs on the VPS permanently. It is the always-on component. It receives messages from the outside world and decides what to do with them. Claude Code runs on my laptop where the codebase lives. It is the coding workhorse. The MCP bridge connects them so each can use the other as a tool.&lt;/p&gt;

&lt;p&gt;Here is the data flow for the most common workflow — a Telegram message triggering a code change:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;Phone (Telegram) → Hermes (VPS) → MCP bridge → Claude Code (local) → filesystem → git → GitHub → Hermes → Telegram → Phone
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The notification loop is closed. I send a message from my phone, the code change happens, and I get a confirmation back on my phone. No manual steps in between.&lt;/p&gt;

&lt;h2&gt;
  
  
  VPS Side Setup
&lt;/h2&gt;

&lt;p&gt;Hermes runs on a Hostinger VPS (Ubuntu 22.04, 4GB RAM). It starts via systemd on boot and stays running. The full config:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml&lt;/span&gt;
&lt;span class="c1"&gt;# Hermes v0.13.0 — VPS production config&lt;/span&gt;

&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

&lt;span class="na"&gt;systemPrompt&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
  &lt;span class="s"&gt;You are a persistent orchestration agent running on a VPS. Your role is:&lt;/span&gt;
  &lt;span class="s"&gt;1. Receive and triage messages from Telegram&lt;/span&gt;
  &lt;span class="s"&gt;2. Maintain a task queue and dispatch coding tasks to Claude Code via MCP&lt;/span&gt;
  &lt;span class="s"&gt;3. Monitor task completion and send confirmations back via Telegram&lt;/span&gt;
  &lt;span class="s"&gt;4. Run scheduled workflows at their designated times&lt;/span&gt;

  &lt;span class="s"&gt;IMPORTANT: Do not write code directly. For any code generation, file editing,&lt;/span&gt;
  &lt;span class="s"&gt;or git operations, use the claude_code tool. You are the orchestrator; Claude&lt;/span&gt;
  &lt;span class="s"&gt;Code is the coder. Your job is planning and coordination.&lt;/span&gt;

&lt;span class="na"&gt;models&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;router&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;provider&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude-haiku-4-5-20251001&lt;/span&gt;
    &lt;span class="na"&gt;temperature&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0.0&lt;/span&gt;
    &lt;span class="na"&gt;use_for&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;task_classification&lt;/span&gt;
  &lt;span class="na"&gt;summarizer&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;provider&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude-haiku-4-5-20251001&lt;/span&gt;
    &lt;span class="na"&gt;temperature&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0.0&lt;/span&gt;
    &lt;span class="na"&gt;use_for&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;result_summarization&lt;/span&gt;

&lt;span class="na"&gt;messaging&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;telegram&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;token&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${TELEGRAM_BOT_TOKEN}"&lt;/span&gt;
    &lt;span class="na"&gt;allowed_chat_ids&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${TELEGRAM_OWNER_CHAT_ID}"&lt;/span&gt;
    &lt;span class="na"&gt;on_message&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;route_to&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;task_queue&lt;/span&gt;
      &lt;span class="na"&gt;confirm_receipt&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

&lt;span class="na"&gt;memory&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;backend&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;sqlite&lt;/span&gt;
  &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;~/.hermes/memory.db&lt;/span&gt;
  &lt;span class="na"&gt;retention_days&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;90&lt;/span&gt;

&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;filesystem&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-filesystem@1.9.2"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/root/storefront"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="na"&gt;git&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-git@0.6.2"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;GIT_AUTHOR_NAME&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Hermes&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;Orchestrator"&lt;/span&gt;
      &lt;span class="na"&gt;GIT_AUTHOR_EMAIL&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;hermes@wowhow.cloud"&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="na"&gt;github&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-github"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;GITHUB_PERSONAL_ACCESS_TOKEN&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${GITHUB_TOKEN}"&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_issues&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;get_issue&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_issue&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;add_issue_comment&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_pull_requests&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_pull_request&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;get_pull_request&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="na"&gt;claude_code&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;mcp"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;serve"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Claude&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;Code&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;—&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;use&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;for&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;all&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;code&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;generation,&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;TypeScript,&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;React,&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;file&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;edits,&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;and&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;git&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;commits"&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;edit_file&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_file&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;read_file&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;run_bash_command&lt;/span&gt;

&lt;span class="na"&gt;serve&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;transport&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;stdio&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;hermes-orchestrator&lt;/span&gt;
  &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
    &lt;span class="s"&gt;Hermes persistent orchestration agent. Accepts natural language task&lt;/span&gt;
    &lt;span class="s"&gt;descriptions, manages a Telegram gateway, runs cron workflows, and&lt;/span&gt;
    &lt;span class="s"&gt;delegates code generation to Claude Code.&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The cron jobs live in a separate file to keep the main config readable:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/cron.yaml&lt;/span&gt;
&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;morning-triage&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="c1"&gt;# 7 AM IST = 1:30 AM UTC on weekdays&lt;/span&gt;
    &lt;span class="na"&gt;schedule&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;30&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;1&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;1-5"&lt;/span&gt;
    &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
      &lt;span class="s"&gt;Pull the last 24 hours of open GitHub issues and pull requests.&lt;/span&gt;
      &lt;span class="s"&gt;Categorize them by priority: blocking, needs-review, backlog.&lt;/span&gt;
      &lt;span class="s"&gt;Create a summary and send it to Telegram with counts and top 3 items.&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-haiku-4-5-20251001&lt;/span&gt;
    &lt;span class="na"&gt;max_steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;12&lt;/span&gt;
    &lt;span class="na"&gt;on_failure&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;notify&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;telegram&lt;/span&gt;

  &lt;span class="na"&gt;pr-triage&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="c1"&gt;# Every 4 hours&lt;/span&gt;
    &lt;span class="na"&gt;schedule&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;0&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*/4&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*"&lt;/span&gt;
    &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
      &lt;span class="s"&gt;Check for pull requests that have been open more than 48 hours without&lt;/span&gt;
      &lt;span class="s"&gt;a review. Post a reminder comment on each one. Do not create new PRs.&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-haiku-4-5-20251001&lt;/span&gt;
    &lt;span class="na"&gt;max_steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;8&lt;/span&gt;
    &lt;span class="na"&gt;dry_run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;

  &lt;span class="na"&gt;weekly-digest&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="c1"&gt;# Sunday 9 PM IST = 3:30 PM UTC&lt;/span&gt;
    &lt;span class="na"&gt;schedule&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;30&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;15&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;0"&lt;/span&gt;
    &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
      &lt;span class="s"&gt;Generate a weekly summary: commits merged, issues closed, PRs opened.&lt;/span&gt;
      &lt;span class="s"&gt;Query GitHub for the past 7 days. Format as markdown and send to Telegram.&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;
    &lt;span class="na"&gt;max_steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;15&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Start cron runner as a daemon:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;hermes cron start &lt;span class="nt"&gt;--config&lt;/span&gt; ~/.hermes/cron.yaml &lt;span class="nt"&gt;--daemon&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The systemd unit file that keeps Hermes running on the VPS:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight systemd"&gt;&lt;code&gt;&lt;span class="c"&gt;# /etc/systemd/system/hermes.service&lt;/span&gt;
&lt;span class="k"&gt;[Unit]&lt;/span&gt;
&lt;span class="nt"&gt;Description&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;Hermes Orchestration Agent
&lt;span class="nt"&gt;After&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;network.target

&lt;span class="k"&gt;[Service]&lt;/span&gt;
&lt;span class="nt"&gt;Type&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;simple
&lt;span class="nt"&gt;User&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;root
&lt;span class="nt"&gt;WorkingDirectory&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;/root
&lt;span class="nt"&gt;ExecStart&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;/usr/local/bin/hermes serve --config /root/.hermes/config.yaml
&lt;span class="nt"&gt;Restart&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;on-failure
&lt;span class="nt"&gt;RestartSec&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;10
&lt;span class="nt"&gt;Environment&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;ANTHROPIC_API_KEY=your-key-here
&lt;span class="nt"&gt;Environment&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;TELEGRAM_BOT_TOKEN=your-token-here
&lt;span class="nt"&gt;Environment&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;TELEGRAM_OWNER_CHAT_ID=your-chat-id-here
&lt;span class="nt"&gt;Environment&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;GITHUB_TOKEN=your-github-token-here

&lt;span class="k"&gt;[Install]&lt;/span&gt;
&lt;span class="nt"&gt;WantedBy&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;multi-user.target
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;





&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;systemctl &lt;span class="nb"&gt;enable &lt;/span&gt;hermes
systemctl start hermes
systemctl status hermes
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Local Side Setup
&lt;/h2&gt;

&lt;p&gt;Claude Code runs on my MacBook where the codebase lives. The configuration that registers Hermes as an MCP server goes in &lt;code&gt;~/.claude.json&lt;/code&gt; (global, so it is available in every project):&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight json"&gt;&lt;code&gt;&lt;span class="err"&gt;#&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="err"&gt;~/.claude.json&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"mcpServers"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"hermes"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"command"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"ssh"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"args"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="w"&gt;
        &lt;/span&gt;&lt;span class="s2"&gt;"-T"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
        &lt;/span&gt;&lt;span class="s2"&gt;"root@your-vps-ip"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
        &lt;/span&gt;&lt;span class="s2"&gt;"hermes mcp serve --config /root/.hermes/config.yaml"&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"description"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"Hermes orchestration agent on VPS — use for Telegram messaging, scheduled tasks, GitHub operations, and multi-step workflows. Do not use for code generation or file editing."&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The SSH transport is the key implementation detail here. Claude Code spawns the MCP server by running the &lt;code&gt;command&lt;/code&gt; + &lt;code&gt;args&lt;/code&gt; and communicating via stdio. By using &lt;code&gt;ssh -T&lt;/code&gt;, the stdio of the local Claude Code process connects via SSH to Hermes running on the VPS. From Claude Code's perspective, it is talking to a local MCP server. From Hermes's perspective, it is receiving MCP protocol messages via stdin from an SSH session.&lt;/p&gt;

&lt;p&gt;This is the cleanest approach I found. The alternatives — running a local Hermes proxy that connects to the VPS, or exposing Hermes on a port and using HTTP transport — both introduce more failure points. The SSH stdio bridge is two commands and a config entry.&lt;/p&gt;

&lt;p&gt;For the SSH connection to work without prompting for credentials, set up key-based auth first:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;ssh-copy-id root@your-vps-ip
&lt;span class="c"&gt;# Verify it works without password:&lt;/span&gt;
ssh &lt;span class="nt"&gt;-T&lt;/span&gt; root@your-vps-ip &lt;span class="nb"&gt;echo&lt;/span&gt; &lt;span class="s2"&gt;"bridge works"&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;You can also use a project-level &lt;code&gt;.mcp.json&lt;/code&gt; if you only want Hermes available in specific repositories:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight json"&gt;&lt;code&gt;&lt;span class="err"&gt;#&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="err"&gt;storefront/.mcp.json&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"mcpServers"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"hermes"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"command"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"ssh"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"args"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="w"&gt;
        &lt;/span&gt;&lt;span class="s2"&gt;"-T"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
        &lt;/span&gt;&lt;span class="s2"&gt;"root@your-vps-ip"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
        &lt;/span&gt;&lt;span class="s2"&gt;"hermes mcp serve --config /root/.hermes/config.yaml"&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"description"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"Hermes orchestration agent — Telegram, GitHub, cron dispatch"&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  The MCP Bridge
&lt;/h2&gt;

&lt;p&gt;The bridge is bidirectional. Claude Code can call Hermes tools. Hermes can call Claude Code tools. Both sides are configured as MCP servers that the other agent registers as a client.&lt;/p&gt;

&lt;p&gt;From Claude Code's perspective, Hermes appears as a set of tools. The primary ones Hermes exposes:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;&lt;p&gt;&lt;code&gt;run_task&lt;/code&gt; — execute a multi-step orchestration task&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;code&gt;send_telegram&lt;/code&gt; — send a message to a specific Telegram chat&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;code&gt;query_memory&lt;/code&gt; — query Hermes's persistent memory store&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;code&gt;schedule_task&lt;/code&gt; — add a one-off task to Hermes's cron queue&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;code&gt;get_github_context&lt;/code&gt; — fetch issues, PRs, and recent commits from the configured repository&lt;/p&gt;&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;From Hermes's perspective, Claude Code appears as a set of tools. The primary ones Claude Code exposes when run as an MCP server:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;&lt;p&gt;&lt;code&gt;edit_file&lt;/code&gt; — make targeted edits to an existing file&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;code&gt;create_file&lt;/code&gt; — create a new file with specified content&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;code&gt;read_file&lt;/code&gt; — read file content&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;&lt;code&gt;run_bash_command&lt;/code&gt; — run a shell command in the project directory&lt;/p&gt;&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Start Claude Code as an MCP server (for Hermes to call):&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;claude mcp serve
&lt;span class="c"&gt;# Listens on stdio — Hermes spawns this process via its claude_code mcpServer config&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The bidirectionality is what makes the system genuinely useful. Without it, you have two separate agents with no way to coordinate. With it, each agent can delegate to the other for tasks in the other's specialty.&lt;/p&gt;

&lt;p&gt;One thing I learned the hard way: the connection from Hermes on the VPS to Claude Code on my local machine requires the local machine to be running and reachable. Hermes can trigger Claude Code tasks only when my MacBook is on and the SSH reverse tunnel is active. For scheduled tasks that run at 7 AM, I need either: (a) my MacBook on, (b) Claude Code also running on the VPS with VPS codebase access, or (c) Hermes falling back to doing the code work itself. I chose option (b) for cron-triggered coding tasks — a second Claude Code instance on the VPS with read/write access to the deployed code.&lt;/p&gt;

&lt;h2&gt;
  
  
  Six Production Patterns
&lt;/h2&gt;

&lt;h3&gt;
  
  
  Pattern 1: Phone → Hermes → Claude Code (Telegram Trigger)
&lt;/h3&gt;

&lt;p&gt;The most-used pattern. I send a Telegram message describing a code change I want. Hermes receives it, decides it is a coding task, dispatches it to Claude Code via the MCP bridge, and sends me a confirmation with the result.&lt;/p&gt;

&lt;p&gt;Example message from my phone:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;Add a "last updated" timestamp to every blog post card on the /blogs listing page.
Format it as "Updated May 16, 2026". Use the published_at field. Mobile-friendly.
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Hermes's processing:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;1. Classify: coding task → route to Claude Code
2. Add context: attach relevant file paths from memory (blog card component location)
3. Call claude_code.run_bash_command: read current component
4. Call claude_code.edit_file: apply the timestamp addition
5. Call claude_code.run_bash_command: run tsc --noEmit to verify
6. Call git tool: commit the change to a feature branch
7. Call github tool: open a draft PR
8. Call send_telegram: "Done. PR #47 opened. Timestamp added to BlogCard.tsx."
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The total elapsed time from my Telegram message to the Telegram confirmation is 90–180 seconds, depending on file size and TypeScript complexity. I am not at my computer for any of it.&lt;/p&gt;

&lt;h3&gt;
  
  
  Pattern 2: Cron → Hermes → Claude Code (Scheduled PR Triage)
&lt;/h3&gt;

&lt;p&gt;Every morning at 7 AM IST, Hermes runs the morning-triage cron job. For issues tagged &lt;code&gt;needs-fix&lt;/code&gt; that have been open more than 3 days, Hermes dispatches a task to Claude Code to generate a fix proposal:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;# Hermes cron task (simplified)
1. List GitHub issues tagged "needs-fix" older than 3 days
2. For each issue:
   a. Read the relevant code file via claude_code.read_file
   b. Call claude_code.run_task: "Propose a fix for this issue. Read the current code and describe the change needed, then implement it in a new branch."
   c. Open a draft PR with the proposed fix
   d. Post a comment on the original issue linking to the PR
3. Send Telegram summary: "Fixed 2 issues overnight. PRs #48, #49 ready for review."
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;This pattern requires Claude Code to be available on the VPS (or the local machine to be on). I keep a Claude Code session running on the VPS in a tmux pane during working hours. For overnight tasks, I use the VPS Claude Code instance with access to the mirrored codebase.&lt;/p&gt;

&lt;h3&gt;
  
  
  Pattern 3: Claude Code → Hermes → Telegram (Completion Notification)
&lt;/h3&gt;

&lt;p&gt;Claude Code can call Hermes tools directly. After completing a long implementation task, Claude Code calls &lt;code&gt;hermes.send_telegram&lt;/code&gt; to notify me:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="err"&gt;#&lt;/span&gt; &lt;span class="nx"&gt;Claude&lt;/span&gt; &lt;span class="nx"&gt;Code&lt;/span&gt; &lt;span class="nx"&gt;side&lt;/span&gt; &lt;span class="err"&gt;—&lt;/span&gt; &lt;span class="nx"&gt;after&lt;/span&gt; &lt;span class="nx"&gt;completing&lt;/span&gt; &lt;span class="nx"&gt;a&lt;/span&gt; &lt;span class="nx"&gt;task&lt;/span&gt;
&lt;span class="err"&gt;#&lt;/span&gt; &lt;span class="nx"&gt;Claude&lt;/span&gt; &lt;span class="nx"&gt;Code&lt;/span&gt; &lt;span class="nx"&gt;calls&lt;/span&gt; &lt;span class="nx"&gt;the&lt;/span&gt; &lt;span class="nx"&gt;hermes&lt;/span&gt; &lt;span class="nx"&gt;MCP&lt;/span&gt; &lt;span class="nx"&gt;tool&lt;/span&gt; &lt;span class="nx"&gt;automatically&lt;/span&gt; &lt;span class="nx"&gt;when&lt;/span&gt; &lt;span class="nx"&gt;instructed&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
&lt;span class="err"&gt;#&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;When you finish, send me a Telegram notification with a summary.&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;

&lt;span class="err"&gt;#&lt;/span&gt; &lt;span class="nx"&gt;The&lt;/span&gt; &lt;span class="nx"&gt;tool&lt;/span&gt; &lt;span class="nx"&gt;call&lt;/span&gt; &lt;span class="nx"&gt;Claude&lt;/span&gt; &lt;span class="nx"&gt;Code&lt;/span&gt; &lt;span class="nx"&gt;makes&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
&lt;span class="nx"&gt;hermes&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;send_telegram&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;message&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;Done: Implemented the dual-stack blog post. Files modified: 2. TypeScript: clean. Build: passing. PR branch: feat/dual-stack-blog-post.&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;
&lt;span class="p"&gt;})&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;This is the simplest pattern and the one I use most often during active development. I start a Claude Code task, tell it to notify me when done, and go do something else. The Telegram ping tells me when to come back.&lt;/p&gt;

&lt;h3&gt;
  
  
  Pattern 4: Hermes Skill → Claude Code Tool
&lt;/h3&gt;

&lt;p&gt;Hermes supports skills — reusable task templates stored in &lt;code&gt;~/.hermes/skills/&lt;/code&gt;. A skill can reference Claude Code as a tool. Here is the blog-writer skill that I use frequently:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/skills/blog-writer.yaml&lt;/span&gt;
&lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;blog-writer&lt;/span&gt;
&lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Write and publish a technical blog post to the WOWHOW storefront&lt;/span&gt;

&lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;research&lt;/span&gt;
    &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
      &lt;span class="s"&gt;Research the topic: ${TOPIC}&lt;/span&gt;
      &lt;span class="s"&gt;Find 3-5 technical sources. Summarize key points and data.&lt;/span&gt;
      &lt;span class="s"&gt;Output: research_summary (markdown)&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;outline&lt;/span&gt;
    &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
      &lt;span class="s"&gt;Create a detailed outline for a ${WORD_COUNT}-word technical blog post&lt;/span&gt;
      &lt;span class="s"&gt;about ${TOPIC}. Use the research from the previous step.&lt;/span&gt;
      &lt;span class="s"&gt;Include all H2 sections, key code blocks, and conclusion.&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;write&lt;/span&gt;
    &lt;span class="na"&gt;tool&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude_code&lt;/span&gt;
    &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
      &lt;span class="s"&gt;Write the full blog post based on the outline. Create the TypeScript&lt;/span&gt;
      &lt;span class="s"&gt;data file at the correct path in src/data/blog-posts/. Follow the&lt;/span&gt;
      &lt;span class="s"&gt;exact format used in existing blog post files. Escape all template&lt;/span&gt;
      &lt;span class="s"&gt;literal variables with backslash. Return the file path when done.&lt;/span&gt;

  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;register&lt;/span&gt;
    &lt;span class="na"&gt;tool&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude_code&lt;/span&gt;
    &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
      &lt;span class="s"&gt;Add the import and spread to src/data/blog-posts.ts. Add the slug&lt;/span&gt;
      &lt;span class="s"&gt;to the POST_ORDER array at position 0. Verify TypeScript compiles.&lt;/span&gt;

  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;notify&lt;/span&gt;
    &lt;span class="na"&gt;tool&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;send_telegram&lt;/span&gt;
    &lt;span class="na"&gt;message&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Blog&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;post&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;created:&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;${TOPIC}.&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;File:&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;${write.result}.&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;Compile:&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;clean."&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Invoke from Telegram:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;/skill blog-writer TOPIC="Hermes dual-stack architecture" WORD_COUNT=4200
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The skill runs end-to-end: research, outline, write (delegated to Claude Code), register (delegated to Claude Code), notify. I get a Telegram message when it is done.&lt;/p&gt;

&lt;h3&gt;
  
  
  Pattern 5: Shared Knowledge Base
&lt;/h3&gt;

&lt;p&gt;Hermes maintains a persistent SQLite memory store. Claude Code reads from &lt;code&gt;CLAUDE.md&lt;/code&gt; and project files. The gap between these two knowledge sources is a real problem — Hermes knows things Claude Code does not, and vice versa.&lt;/p&gt;

&lt;p&gt;I bridge this in two ways. First, I have a cron job that exports Hermes's memory to a markdown file that Claude Code can read:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/cron.yaml&lt;/span&gt;
  &lt;span class="na"&gt;memory-sync&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;schedule&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;0&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*"&lt;/span&gt;    &lt;span class="c1"&gt;# every hour&lt;/span&gt;
    &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
      &lt;span class="s"&gt;Export all memory entries tagged "architecture" or "decisions" to&lt;/span&gt;
      &lt;span class="s"&gt;/root/storefront/storefront/.hermes-context.md in markdown format.&lt;/span&gt;
      &lt;span class="s"&gt;Format: ## [tag] &lt;/span&gt;
 &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;key&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;&lt;span class="err"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;value&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt; 

    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-haiku-4-5-20251001&lt;/span&gt;
    &lt;span class="na"&gt;max_steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;5&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Second, I add a reference to this file in &lt;code&gt;CLAUDE.md&lt;/code&gt;:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight markdown"&gt;&lt;code&gt;&lt;span class="gh"&gt;# In storefront/CLAUDE.md, add:&lt;/span&gt;
&lt;span class="gu"&gt;## Hermes Context&lt;/span&gt;
Read &lt;span class="sb"&gt;`.hermes-context.md`&lt;/span&gt; for decisions and context that Hermes has recorded.
This file is auto-updated hourly by Hermes's memory-sync cron job.
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The reverse direction — Claude Code writing to Hermes memory — works via the &lt;code&gt;hermes.query_memory&lt;/code&gt; and (when available) &lt;code&gt;hermes.write_memory&lt;/code&gt; tools. I instruct Claude Code to record important architectural decisions to Hermes memory at the end of significant tasks. This keeps Hermes's context current without manual updates.&lt;/p&gt;

&lt;h3&gt;
  
  
  Pattern 6: Multi-Agent Kanban with Claude Code as Worker
&lt;/h3&gt;

&lt;p&gt;For larger features that span multiple sessions, I use Hermes as a Kanban board manager and Claude Code as the task worker. Hermes maintains a task list in its memory store, assigns tasks, tracks completion, and dispatches the next task when the previous one finishes.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# Hermes task queue in memory (simplified schema)&lt;/span&gt;
&lt;span class="na"&gt;tasks&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;T001&lt;/span&gt;
    &lt;span class="na"&gt;title&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Add&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;dual-stack&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;blog&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;post"&lt;/span&gt;
    &lt;span class="na"&gt;status&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;done&lt;/span&gt;
    &lt;span class="na"&gt;assigned_to&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude_code&lt;/span&gt;
    &lt;span class="na"&gt;completed_at&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2026-05-16T22:00:00Z"&lt;/span&gt;

  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;T002&lt;/span&gt;
    &lt;span class="na"&gt;title&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Add&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;Hermes&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;skill&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;index&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;page"&lt;/span&gt;
    &lt;span class="na"&gt;status&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;in_progress&lt;/span&gt;
    &lt;span class="na"&gt;assigned_to&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude_code&lt;/span&gt;
    &lt;span class="na"&gt;started_at&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;2026-05-16T22:15:00Z"&lt;/span&gt;

  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;T003&lt;/span&gt;
    &lt;span class="na"&gt;title&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Update&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;tools&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;registry&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;with&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;5&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;new&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;tools"&lt;/span&gt;
    &lt;span class="na"&gt;status&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;pending&lt;/span&gt;
    &lt;span class="na"&gt;assigned_to&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude_code&lt;/span&gt;
    &lt;span class="na"&gt;depends_on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;T002&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;When Claude Code completes T002, it calls &lt;code&gt;hermes.run_task&lt;/code&gt; with a task completion report. Hermes marks T002 done, checks dependencies, and dispatches T003 to Claude Code automatically. I get a Telegram update after each task completes.&lt;/p&gt;

&lt;p&gt;This pattern is useful for late-night work — I set up the Kanban queue before sleeping and wake up to a Telegram thread showing what was completed overnight. Claude Code on the VPS handles the actual execution. Hermes handles sequencing and notification.&lt;/p&gt;

&lt;h2&gt;
  
  
  What Broke
&lt;/h2&gt;

&lt;p&gt;This section is the most important one. Architectural diagrams always look cleaner than the implementation.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;MCP stdio bridge latency.&lt;/strong&gt; The SSH stdio bridge adds 200–400ms to every MCP tool call. For interactive use this is borderline acceptable. For workflows with 15+ tool calls, you notice it accumulate. A Hermes task that calls Claude Code 10 times takes 2–4 seconds just in bridge overhead before accounting for model inference time. I have not found a way to reduce this without switching to a persistent TCP connection, which introduces its own complexity.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Session state is not shared.&lt;/strong&gt; Hermes has its SQLite memory store. Claude Code has CLAUDE.md and project context. There is no live shared state — the two agents do not see each other's current reasoning. When Hermes dispatches a task to Claude Code, Claude Code has no awareness of what Hermes is "thinking about" beyond what Hermes explicitly passes in the task description. I compensate by writing verbose task descriptions, but this is a real limitation. Long tasks sometimes lose context mid-execution because the task description did not include a fact that seemed obvious from Hermes's perspective.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Skill format mismatch.&lt;/strong&gt; Hermes skills use Hermes's YAML format with Hermes-specific interpolation syntax. Claude Code skills use a different format. You cannot share skill definitions between the two systems — you maintain two separate skill libraries. I tried to abstract this into a shared format and gave up after a day. The formats are different enough that a translation layer would be more maintenance than two separate libraries.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Claude Code MCP server is not designed for concurrent access.&lt;/strong&gt; When Hermes runs two cron jobs simultaneously and both dispatch tasks to Claude Code, you get race conditions. The second task waits for the first to complete (or fails with a lock error). I now stagger cron jobs by at least 5 minutes and ensure no two jobs can both dispatch to Claude Code in the same window.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;SSH tunnel drops.&lt;/strong&gt; If the SSH connection drops mid-task, the MCP bridge silently dies. Hermes does not always detect this cleanly — sometimes it retries the same tool call instead of reporting a connection failure. I added a keepalive to the SSH config and a health check to the Hermes config, but this remains the flakiest part of the setup.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight ssh"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.ssh/config — add for the VPS connection&lt;/span&gt;
&lt;span class="k"&gt;Host&lt;/span&gt; your-vps-ip
  &lt;span class="k"&gt;ServerAliveInterval&lt;/span&gt; &lt;span class="m"&gt;30&lt;/span&gt;
  &lt;span class="k"&gt;ServerAliveCountMax&lt;/span&gt; &lt;span class="m"&gt;3&lt;/span&gt;
  &lt;span class="k"&gt;ConnectTimeout&lt;/span&gt; &lt;span class="m"&gt;10&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  The Workflow That Stuck
&lt;/h2&gt;

&lt;p&gt;After two weeks of debugging and two more weeks of daily use, one workflow pattern has become my default and I expect it to stay:&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Phone-driven development.&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Morning: Wake up. Open Telegram. Check the overnight Hermes summary (morning-triage cron). It tells me what is open, what needs review, and what broke. I read it on my phone before getting out of bed.&lt;/p&gt;

&lt;p&gt;During the day: When I think of a code change while away from my computer, I send a Telegram message. Hermes routes it to the task queue. When my computer is on and Claude Code is running, the task executes. I get a confirmation when it is done. I do not need to be at the computer to initiate the work or to know when it is complete.&lt;/p&gt;

&lt;p&gt;Evening: I review what was done. If something needs manual review, the PR is already open. I read it, request any changes via GitHub (or via Telegram → Hermes → GitHub comment), and move on.&lt;/p&gt;

&lt;p&gt;The dual-stack did not change how I write code — Claude Code does that the same as before. What changed is the coordination layer around the coding. Scheduling, notification, context from the outside world — all of that now runs through Hermes, always-on, without me needing to be at my desk to trigger or monitor it.&lt;/p&gt;

&lt;p&gt;The question people usually ask at this point: is it worth the setup complexity? For a solo founder running a product with 1,800+ items, a blog pipeline, and daily SEO and coding work — yes. If you are doing weekend projects or one-off builds, probably not. The setup cost is three to four hours of real work. The maintenance burden is low once it is running. The payoff is a development loop that runs while I sleep and notifies me on my phone.&lt;/p&gt;

&lt;h2&gt;
  
  
  Full Config Summary
&lt;/h2&gt;

&lt;p&gt;All the config files in one place for reference:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;# VPS: ~/.hermes/config.yaml — Hermes orchestrator
# VPS: ~/.hermes/cron.yaml — Scheduled jobs
# VPS: /etc/systemd/system/hermes.service — Auto-start
# Local: ~/.claude.json — Claude Code global MCP registration
# Local: storefront/.mcp.json — Project-level MCP registration (optional)
# Local: ~/.ssh/config — SSH keepalive settings
# Shared: storefront/.hermes-context.md — Hourly memory sync output
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The minimum viable dual-stack is three files: &lt;code&gt;~/.hermes/config.yaml&lt;/code&gt; on the VPS with the &lt;code&gt;claude_code&lt;/code&gt; mcpServer entry, &lt;code&gt;~/.claude.json&lt;/code&gt; on your local machine with the &lt;code&gt;hermes&lt;/code&gt; mcpServer entry using SSH transport, and SSH key auth set up between the two machines. Everything else — cron, Telegram, memory sync, skills — layers on top of that foundation.&lt;/p&gt;

&lt;h2&gt;
  
  
  Start with the minimum. Get the bridge working. Run a test task end-to-end. Then add the pieces that match your specific workflow.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/hermes-claude-code-dual-stack-orchestrator-coder-architecture-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>hermesclaude</category>
      <category>hermesagent</category>
      <category>claudecode</category>
      <category>hermesmcp</category>
    </item>
    <item>
      <title>I Wired Claude Code Into Hermes Agent (And Hermes Into Claude Code): The Full Tool Gateway Reference</title>
      <dc:creator>Anup Karanjkar</dc:creator>
      <pubDate>Thu, 21 May 2026 15:11:12 +0000</pubDate>
      <link>https://forem.com/akaranjkar08/i-wired-claude-code-into-hermes-agent-and-hermes-into-claude-code-the-full-tool-gateway-reference-474l</link>
      <guid>https://forem.com/akaranjkar08/i-wired-claude-code-into-hermes-agent-and-hermes-into-claude-code-the-full-tool-gateway-reference-474l</guid>
      <description>&lt;p&gt;&lt;strong&gt;The Hermes Tool Gateway is the piece of the Hermes architecture that most documentation glosses over.&lt;/strong&gt; Every guide shows you how to start Hermes, pick a model, and chat. Almost none of them explain how the MCP (Model Context Protocol) integration actually works in production — specifically, how to configure Hermes as an MCP &lt;em&gt;client&lt;/em&gt; so it can call external tools, and simultaneously as an MCP &lt;em&gt;server&lt;/em&gt; so Claude Code or any other agent can call Hermes as a tool. That bidirectionality is what makes Hermes genuinely useful in a multi-agent stack.&lt;/p&gt;

&lt;p&gt;I spent a week wiring Hermes v0.13.0 into my production setup — Claude Code as the primary coder, Hermes as the orchestration layer, with shared tool access across both. What follows are 12 working patterns from that process, in increasing order of complexity. Every YAML block is a copy-paste starting point. I have run each of these in production and debugged the failure modes so you do not have to.&lt;/p&gt;

&lt;p&gt;Before we get into the patterns, one prerequisite: run the sanity check. Everything else depends on your environment being clean.&lt;/p&gt;

&lt;h2&gt;
  
  
  Setup Step Zero: The Doctor Check
&lt;/h2&gt;

&lt;p&gt;Before touching a single config file, run Hermes's built-in diagnostics command:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes doctor
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;A healthy environment produces output that looks like this:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;[hermes doctor] Checking environment...

  ✓ hermes binary          v0.13.0
  ✓ config file            ~/.hermes/config.yaml (found)
  ✓ default model          anthropic/claude-sonnet-4-6 (reachable)
  ✓ API credentials        ANTHROPIC_API_KEY set (not expired)
  ✓ MCP runtime            @modelcontextprotocol/server v1.9.2
  ✓ Node.js                v22.4.0 (required ≥ 20)
  ✓ filesystem permissions ~/.hermes/ writable
  ✓ log directory          ~/.hermes/logs/ writable

[hermes doctor] All checks passed. Tool gateway ready.
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;If you see any red &lt;code&gt;✗&lt;/code&gt; entries, fix them before proceeding. The two most common failures are a stale &lt;code&gt;ANTHROPIC_API_KEY&lt;/code&gt; and a Node.js version below 20. The MCP runtime in v0.13.0 uses native &lt;code&gt;fetch&lt;/code&gt; and async generators that require Node 20+. On Node 18, you will get silent failures in the tool invocation layer — no error, just missing tool calls. Upgrade first.&lt;/p&gt;

&lt;p&gt;If the config file is missing entirely:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes init
# Creates ~/.hermes/config.yaml with defaults
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Pattern 1: Outbound — Filesystem MCP Server
&lt;/h2&gt;

&lt;p&gt;The simplest outbound MCP connection gives Hermes read and write access to a directory on your local filesystem. This is the foundation for every pattern that follows — once you understand how the &lt;code&gt;mcpServers&lt;/code&gt; key works in &lt;code&gt;config.yaml&lt;/code&gt;, the rest of the patterns are variations on the same structure.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml&lt;/span&gt;
&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;filesystem&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;-y&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-filesystem"&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;/Users/yourname/projects&lt;/span&gt;        &lt;span class="c1"&gt;# root directory Hermes can access&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;NODE_ENV&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;production&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;With this config, Hermes gains the following tools automatically: &lt;code&gt;read_file&lt;/code&gt;, &lt;code&gt;write_file&lt;/code&gt;, &lt;code&gt;list_directory&lt;/code&gt;, &lt;code&gt;create_directory&lt;/code&gt;, &lt;code&gt;move_file&lt;/code&gt;, &lt;code&gt;search_files&lt;/code&gt;, and &lt;code&gt;get_file_info&lt;/code&gt;. You do not define these tools yourself — they come from the MCP server binary. Hermes discovers them at startup via the MCP handshake and makes them available to the model during every conversation.&lt;/p&gt;

&lt;p&gt;Verify it is working:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes tools list
# Expected output includes:
# [mcp:filesystem] read_file
# [mcp:filesystem] write_file
# [mcp:filesystem] list_directory
# ... (7 tools total)
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;command: npx&lt;/code&gt; pattern is important. Hermes spawns the MCP server as a child process using stdio transport. The &lt;code&gt;-y&lt;/code&gt; flag on &lt;code&gt;npx&lt;/code&gt; auto-installs the package if it is not cached. In production I pin the version to avoid surprises:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;-y&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-filesystem@1.9.2"&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;/Users/yourname/projects&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Pattern 2: Outbound — GitHub Issues with Tool Whitelist
&lt;/h2&gt;

&lt;p&gt;The GitHub MCP server exposes a large surface area by default — pull request management, repo creation, branch operations, issue management, gist operations. In most workflows you only want a subset. Use the &lt;code&gt;include&lt;/code&gt; key to whitelist exactly the tools Hermes is allowed to call:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml&lt;/span&gt;
&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;github&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;-y&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-github"&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;GITHUB_PERSONAL_ACCESS_TOKEN&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${GITHUB_TOKEN}"&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_issues&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;get_issue&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_issue&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;add_issue_comment&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_pull_requests&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;get_pull_request&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;include&lt;/code&gt; key is a capability filter. Tools not in the list are invisible to the model — they are filtered out during the MCP handshake response. This matters for two reasons. First, it reduces the tool count in the model's context, which measurably improves tool selection accuracy. When Hermes has 60 GitHub tools available, it occasionally picks the wrong one. With 6 relevant tools, it consistently picks correctly. Second, it eliminates accidental destructive operations. A model that cannot see &lt;code&gt;delete_repository&lt;/code&gt; cannot call &lt;code&gt;delete_repository&lt;/code&gt;, no matter what a user asks.&lt;/p&gt;

&lt;p&gt;Note the &lt;code&gt;${GITHUB_TOKEN}&lt;/code&gt; syntax — Hermes resolves environment variables in the config file at startup. Set the variable in your shell profile before running Hermes. Never hardcode tokens in the config file.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pattern 3: Outbound — OAuth-Protected Remote Servers (Stripe Example)
&lt;/h2&gt;

&lt;p&gt;Not all MCP servers run as local stdio processes. Some run as remote HTTP servers that use OAuth for authentication. The Stripe MCP server is the canonical example, and it is the pattern I use for payment-related Hermes tasks:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml&lt;/span&gt;
&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;stripe&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;transport&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;http&lt;/span&gt;
    &lt;span class="na"&gt;url&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;https://mcp.stripe.com/v1"&lt;/span&gt;
    &lt;span class="na"&gt;auth&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;oauth2&lt;/span&gt;
      &lt;span class="na"&gt;clientId&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${STRIPE_MCP_CLIENT_ID}"&lt;/span&gt;
      &lt;span class="na"&gt;clientSecret&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${STRIPE_MCP_CLIENT_SECRET}"&lt;/span&gt;
      &lt;span class="na"&gt;tokenUrl&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;https://mcp.stripe.com/oauth/token"&lt;/span&gt;
      &lt;span class="na"&gt;scopes&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;customers:read&lt;/span&gt;
        &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;charges:read&lt;/span&gt;
        &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;subscriptions:read&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_customers&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;retrieve_customer&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_charges&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;retrieve_subscription&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;transport: http&lt;/code&gt; key switches Hermes from stdio to HTTP/SSE transport. Hermes handles the OAuth token lifecycle automatically — it fetches a token on first use and refreshes it before expiry. You do not need to manage token rotation in your application code.&lt;/p&gt;

&lt;p&gt;For the Stripe MCP server specifically, request only read scopes unless your workflow explicitly requires write operations. Hermes is good at knowing when to call tools, but defense in depth means limiting what a tool can do even when called correctly. I use &lt;code&gt;customers:read&lt;/code&gt;, &lt;code&gt;charges:read&lt;/code&gt;, and &lt;code&gt;subscriptions:read&lt;/code&gt; for my billing workflow — no write access, no refund operations, no configuration changes.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pattern 4: Multi-Server Composition
&lt;/h2&gt;

&lt;p&gt;The real power of the &lt;code&gt;mcpServers&lt;/code&gt; key is that you can define multiple servers simultaneously. Hermes aggregates all the tools from all connected servers into a single unified toolset. The model sees one flat list of available tools and picks from it based on the task. Here is my baseline five-server composition:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml&lt;/span&gt;
&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

&lt;span class="na"&gt;systemPrompt&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
  &lt;span class="s"&gt;You are a senior developer assistant with access to filesystem tools,&lt;/span&gt;
  &lt;span class="s"&gt;git operations, GitHub API, a Postgres database, and project documentation.&lt;/span&gt;
  &lt;span class="s"&gt;Always prefer reading documentation before modifying code. Always commit&lt;/span&gt;
  &lt;span class="s"&gt;changes to git before marking a task complete.&lt;/span&gt;

&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;filesystem&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-filesystem@1.9.2"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/Users/yourname/projects"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

  &lt;span class="na"&gt;git&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-git@0.6.2"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;GIT_AUTHOR_NAME&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Hermes&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;Agent"&lt;/span&gt;
      &lt;span class="na"&gt;GIT_AUTHOR_EMAIL&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;hermes@yourproject.local"&lt;/span&gt;

  &lt;span class="na"&gt;github&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-github"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;GITHUB_PERSONAL_ACCESS_TOKEN&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${GITHUB_TOKEN}"&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_issues&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;get_issue&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_issue&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;add_issue_comment&lt;/span&gt;

  &lt;span class="na"&gt;postgres&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;-y&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-postgres"&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${DATABASE_URL}"&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;query&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_tables&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;describe_table&lt;/span&gt;

  &lt;span class="na"&gt;docs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-fetch"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;ALLOWED_DOMAINS&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;docs.yourproject.com,api.yourproject.com"&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;fetch&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;search&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;systemPrompt&lt;/code&gt; key at the top-level config is essential in multi-server setups. Without a system prompt, the model treats all tools as equally available and equally appropriate. With a system prompt that sets behavioral priorities — "read documentation before modifying code", "commit before marking complete" — tool selection becomes more intentional and the overall task completion quality improves significantly.&lt;/p&gt;

&lt;p&gt;One thing to watch in multi-server setups: tool name collisions. If two MCP servers expose a tool called &lt;code&gt;search&lt;/code&gt;, Hermes namespaces them as &lt;code&gt;mcp:docs:search&lt;/code&gt; and &lt;code&gt;mcp:github:search&lt;/code&gt; in its internal registry but presents both to the model. Whether the model picks the right one depends heavily on how well the server's tool descriptions distinguish the two operations. If you see the model consistently picking the wrong &lt;code&gt;search&lt;/code&gt; variant, add an &lt;code&gt;include&lt;/code&gt; filter to one of the servers to remove the ambiguous tool.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pattern 5: Inbound — Hermes as MCP Server
&lt;/h2&gt;

&lt;p&gt;Everything so far has been outbound: Hermes calling external MCP servers. Pattern 5 flips the direction. Hermes itself becomes an MCP server that external agents — Claude Code, Cursor, custom tools — can call as a tool.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;# Start Hermes as an MCP server
hermes mcp serve   --transport stdio   --name "hermes-orchestrator"   --description "Multi-step task orchestrator with filesystem, git, and GitHub access"   --port 0
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;When run in this mode, Hermes exposes itself via stdio using the standard MCP protocol. External agents connect to it exactly as they connect to any other MCP server. From the external agent's perspective, Hermes is a tool with one primary method: &lt;code&gt;run_task&lt;/code&gt;, which accepts a natural-language task description and returns the result of Hermes completing that task using its own tool chain.&lt;/p&gt;

&lt;p&gt;To make this permanent and auto-starting, configure it in a &lt;code&gt;hermes-server.yaml&lt;/code&gt;:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/server.yaml&lt;/span&gt;
&lt;span class="na"&gt;serve&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;transport&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;stdio&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;hermes-orchestrator&lt;/span&gt;
  &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
    &lt;span class="s"&gt;Hermes orchestration agent. Accepts natural language task descriptions&lt;/span&gt;
    &lt;span class="s"&gt;and completes them autonomously using filesystem, git, GitHub, and&lt;/span&gt;
    &lt;span class="s"&gt;Postgres tools. Returns structured results with tool call traces.&lt;/span&gt;
  &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;run_task&lt;/span&gt;
      &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
        &lt;span class="s"&gt;Execute a multi-step development task. Provide a clear task description&lt;/span&gt;
        &lt;span class="s"&gt;including success criteria. Hermes will plan and execute the task using&lt;/span&gt;
        &lt;span class="s"&gt;its available tools and return a structured result.&lt;/span&gt;
      &lt;span class="na"&gt;inputSchema&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;object&lt;/span&gt;
        &lt;span class="na"&gt;properties&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;string&lt;/span&gt;
            &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Natural language task description with success criteria&lt;/span&gt;
          &lt;span class="na"&gt;context&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;string&lt;/span&gt;
            &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Optional additional context (file paths, constraints, etc.)&lt;/span&gt;
          &lt;span class="na"&gt;max_steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;integer&lt;/span&gt;
            &lt;span class="na"&gt;default&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;20&lt;/span&gt;
            &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Maximum tool calls before halting&lt;/span&gt;
        &lt;span class="na"&gt;required&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Start it:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes mcp serve --config ~/.hermes/server.yaml
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Pattern 6: The Dual-Stack — Claude Code as Coder, Hermes as Orchestrator
&lt;/h2&gt;

&lt;p&gt;This is the pattern I use every day and the one that makes the biggest difference to how I work. Claude Code handles code generation, edits, and TypeScript/React tasks. Hermes handles orchestration — running sequences of tasks, managing git state, interacting with GitHub and Postgres, and coordinating work across multiple files and tools. Both agents share tool access, but they have different roles.&lt;/p&gt;

&lt;p&gt;Here is how to wire it up. First, configure Hermes to expose itself as an MCP server AND connect to Claude Code's tool surface:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml (Hermes side)&lt;/span&gt;
&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

&lt;span class="na"&gt;systemPrompt&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
  &lt;span class="s"&gt;You are an orchestration agent. You plan multi-step development workflows,&lt;/span&gt;
  &lt;span class="s"&gt;manage git state, coordinate with GitHub, and delegate code-generation&lt;/span&gt;
  &lt;span class="s"&gt;subtasks to Claude Code when needed. You do not write code directly — you&lt;/span&gt;
  &lt;span class="s"&gt;describe what code is needed and call the claude_code tool to generate it.&lt;/span&gt;
  &lt;span class="s"&gt;Always verify git status before and after code changes.&lt;/span&gt;

&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;filesystem&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-filesystem@1.9.2"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/Users/yourname/projects"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

  &lt;span class="na"&gt;git&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-git@0.6.2"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

  &lt;span class="na"&gt;github&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-github"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;GITHUB_PERSONAL_ACCESS_TOKEN&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${GITHUB_TOKEN}"&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_issues&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_pull_request&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;add_issue_comment&lt;/span&gt;

&lt;span class="na"&gt;serve&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;transport&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;stdio&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;hermes-orchestrator&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Second, add Hermes as an MCP server in Claude Code's &lt;code&gt;.claude.json&lt;/code&gt;:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight json"&gt;&lt;code&gt;&lt;span class="err"&gt;#&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="err"&gt;~/.claude.json&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="err"&gt;(Claude&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="err"&gt;Code&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="err"&gt;side)&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"mcpServers"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"hermes"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"command"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"hermes"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"args"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"mcp"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"serve"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"--config"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"/Users/yourname/.hermes/config.yaml"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"description"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"Hermes orchestration agent — use for multi-step tasks, git workflows, GitHub operations, and database queries"&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Third, add Claude Code as an MCP server in Hermes's config, completing the bidirectional bridge:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# Add to ~/.hermes/config.yaml under mcpServers:&lt;/span&gt;
  &lt;span class="na"&gt;claude_code&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;mcp"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;serve"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Claude&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;Code&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;—&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;use&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;for&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;code&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;generation,&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;TypeScript,&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;React,&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;file&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;edits"&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;edit_file&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_file&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;read_file&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;run_bash_command&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;With both sides configured, the workflow looks like this in practice:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;&lt;p&gt;I describe a feature to Hermes: "Implement the UserProfile component, wire it to the /api/profile endpoint, commit to a feature branch, and open a draft PR."&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;Hermes plans the steps, reads the existing codebase via filesystem tools, and calls Claude Code via MCP to generate the actual component code.&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;Claude Code returns the generated code. Hermes writes it to disk via filesystem tools, runs the git commit via git tools, and creates the PR via GitHub tools.&lt;/p&gt;&lt;/li&gt;
&lt;li&gt;&lt;p&gt;Hermes reports the PR URL and a summary of what was done.&lt;/p&gt;&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;Neither agent is trying to do everything. Claude Code is better at code generation. Hermes is better at multi-step planning and tool orchestration. The dual-stack lets each do what it does best.&lt;/p&gt;

&lt;p&gt;One critical thing to get right: the &lt;code&gt;systemPrompt&lt;/code&gt; on the Hermes side must explicitly tell it NOT to write code directly and to call Claude Code for code generation. Without that instruction, Hermes will try to generate code itself using its own model — which works, but loses the specialization advantage. The system prompt is the architectural boundary.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pattern 7: Cron-Driven Scheduled MCP Workflows
&lt;/h2&gt;

&lt;p&gt;Hermes supports scheduled task execution via its cron integration. This is useful for automated workflows — daily digest emails, scheduled database cleanups, periodic GitHub sync, and similar recurring operations. The cron config goes in a separate &lt;code&gt;cron.yaml&lt;/code&gt; file:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/cron.yaml&lt;/span&gt;
&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;daily-digest&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="c1"&gt;# Run at 8 AM IST (2:30 AM UTC) every weekday&lt;/span&gt;
    &lt;span class="na"&gt;schedule&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;30&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;2&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;1-5"&lt;/span&gt;
    &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
      &lt;span class="s"&gt;1. Query the Postgres database for all open issues created in the last 24 hours.&lt;/span&gt;
      &lt;span class="s"&gt;2. Fetch the corresponding GitHub issues to get current status.&lt;/span&gt;
      &lt;span class="s"&gt;3. Generate a markdown summary grouped by priority.&lt;/span&gt;
      &lt;span class="s"&gt;4. Create a new page in the project docs directory with today's date as the filename.&lt;/span&gt;
      &lt;span class="s"&gt;5. Post the summary as a comment on the tracking GitHub issue #1.&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-haiku-4-5-20251001&lt;/span&gt;    &lt;span class="c1"&gt;# cheaper model for scheduled tasks&lt;/span&gt;
    &lt;span class="na"&gt;max_steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;15&lt;/span&gt;
    &lt;span class="na"&gt;on_failure&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;notify&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;hermes-alerts"&lt;/span&gt;    &lt;span class="c1"&gt;# Telegram integration (configured separately)&lt;/span&gt;

  &lt;span class="na"&gt;weekly-cleanup&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="c1"&gt;# Every Sunday at midnight UTC&lt;/span&gt;
    &lt;span class="na"&gt;schedule&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;0&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;0&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;*&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;0"&lt;/span&gt;
    &lt;span class="na"&gt;task&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
      &lt;span class="s"&gt;Query the Postgres database for rows in the task_log table older than 30 days.&lt;/span&gt;
      &lt;span class="s"&gt;Delete them in batches of 100 to avoid locking. Report the row count deleted.&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-haiku-4-5-20251001&lt;/span&gt;
    &lt;span class="na"&gt;max_steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;10&lt;/span&gt;
    &lt;span class="na"&gt;dry_run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;    &lt;span class="c1"&gt;# set to true to preview without executing&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Start the cron runner:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes cron start --config ~/.hermes/cron.yaml --daemon
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Check cron status:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes cron status
# Output:
# daily-digest    next run: 2026-05-17T02:30:00Z    last: completed (14 steps, 42s)
# weekly-cleanup  next run: 2026-05-17T00:00:00Z    last: completed (8 steps, 12s)
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;model&lt;/code&gt; override in cron jobs is important. Scheduled tasks that run unattended do not need the highest-capability model. Using Haiku for daily digest generation costs roughly 10x less than Sonnet and produces equivalent quality for structured, well-defined tasks. I only use Sonnet or Opus in cron jobs when the task involves genuine reasoning or ambiguous input.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pattern 8: Per-Tool Gateway Routing with use_gateway
&lt;/h2&gt;

&lt;p&gt;By default, all MCP tool calls go through Hermes's primary model. The &lt;code&gt;use_gateway&lt;/code&gt; key lets you route specific tool calls through a different configuration — a different model, different retry behavior, or a different timeout. This is useful when one tool in your stack is unreliable or slow:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml&lt;/span&gt;
&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;filesystem&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-filesystem@1.9.2"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/Users/yourname/projects"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

  &lt;span class="na"&gt;slow-api&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@company/internal-mcp-server"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;API_URL&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${INTERNAL_API_URL}"&lt;/span&gt;
      &lt;span class="na"&gt;API_KEY&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${INTERNAL_API_KEY}"&lt;/span&gt;
    &lt;span class="na"&gt;use_gateway&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;timeout_seconds&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;120&lt;/span&gt;      &lt;span class="c1"&gt;# Default is 30s — this server is slow&lt;/span&gt;
      &lt;span class="na"&gt;retry&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;max_attempts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;3&lt;/span&gt;
        &lt;span class="na"&gt;backoff&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;exponential&lt;/span&gt;
        &lt;span class="na"&gt;initial_delay_ms&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;1000&lt;/span&gt;
      &lt;span class="na"&gt;circuit_breaker&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;failure_threshold&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;5&lt;/span&gt;    &lt;span class="c1"&gt;# Open circuit after 5 consecutive failures&lt;/span&gt;
        &lt;span class="na"&gt;recovery_timeout_s&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;60&lt;/span&gt;  &lt;span class="c1"&gt;# Try again after 60s&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;use_gateway&lt;/code&gt; block is per-server, not per-tool. Every tool from &lt;code&gt;slow-api&lt;/code&gt; inherits the 120-second timeout and exponential backoff. If you need different timeouts for different tools from the same server, you need to run two instances of the server with different configs — there is no per-tool timeout override in v0.13.0.&lt;/p&gt;

&lt;p&gt;The circuit breaker is the most important part of the &lt;code&gt;use_gateway&lt;/code&gt; config for production. Without it, Hermes will keep trying a failing MCP server on every tool call, accumulating timeouts and burning model tokens on retries. With a circuit breaker, after 5 consecutive failures the server is marked as unavailable for 60 seconds. Hermes continues with the remaining tools and reports that the unavailable server's tools are offline. This degrades gracefully instead of hanging.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pattern 9: Auxiliary Models for Sub-Tasks
&lt;/h2&gt;

&lt;p&gt;Hermes supports a &lt;code&gt;models&lt;/code&gt; block that lets you define auxiliary model configurations for specific purposes. The three patterns I use most are: a fast router model for initial task classification, a reasoning model for complex multi-step planning, and a cheap model for tool result summarization:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml&lt;/span&gt;
&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;    &lt;span class="c1"&gt;# primary model&lt;/span&gt;

&lt;span class="na"&gt;models&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;router&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;provider&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude-haiku-4-5-20251001&lt;/span&gt;
    &lt;span class="na"&gt;temperature&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0.0&lt;/span&gt;                   &lt;span class="c1"&gt;# deterministic routing decisions&lt;/span&gt;
    &lt;span class="na"&gt;use_for&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;task_classification&lt;/span&gt;       &lt;span class="c1"&gt;# Hermes uses this model to classify tasks before routing&lt;/span&gt;

  &lt;span class="na"&gt;reasoner&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;provider&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude-opus-4-7&lt;/span&gt;
    &lt;span class="na"&gt;temperature&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0.3&lt;/span&gt;
    &lt;span class="na"&gt;use_for&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;complex_planning&lt;/span&gt;          &lt;span class="c1"&gt;# Used when task requires multi-step planning &amp;gt; 10 steps&lt;/span&gt;
    &lt;span class="na"&gt;max_tokens&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;8192&lt;/span&gt;

  &lt;span class="na"&gt;summarizer&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;provider&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude-haiku-4-5-20251001&lt;/span&gt;
    &lt;span class="na"&gt;temperature&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0.0&lt;/span&gt;
    &lt;span class="na"&gt;use_for&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;result_summarization&lt;/span&gt;      &lt;span class="c1"&gt;# Condenses verbose tool output before adding to context&lt;/span&gt;

&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;filesystem&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-filesystem@1.9.2"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/Users/yourname/projects"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

&lt;span class="na"&gt;routing&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;classify_tasks&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;                 &lt;span class="c1"&gt;# Enable automatic task classification via router model&lt;/span&gt;
  &lt;span class="na"&gt;auto_route_complex&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;             &lt;span class="c1"&gt;# Auto-upgrade to reasoner for complex tasks&lt;/span&gt;
  &lt;span class="na"&gt;complexity_threshold&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;8&lt;/span&gt;              &lt;span class="c1"&gt;# Tasks requiring &amp;gt; 8 steps use the reasoner model&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The &lt;code&gt;routing.complexity_threshold&lt;/code&gt; is calibrated by trial and error. At 8, about 20% of my tasks get routed to Opus. Those are the tasks where the reasoning model's stronger multi-step planning genuinely produces better outcomes. If you set it too low, you pay Opus rates for tasks that Sonnet handles fine. If you set it too high, complex orchestration tasks fail partway through because Sonnet loses the thread.&lt;/p&gt;

&lt;p&gt;The summarizer model is particularly valuable in multi-server setups where some tools return verbose output. Postgres &lt;code&gt;query&lt;/code&gt; results with hundreds of rows, GitHub API responses with nested JSON, fetch results from documentation pages — all of these can balloon the context window quickly. The summarizer runs after each tool call and condenses the output to the relevant facts before it goes into the conversation context. This alone cuts my average token cost by roughly 30% on database-heavy workflows.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pattern 10: Fallback Provider for Resilience
&lt;/h2&gt;

&lt;p&gt;If Anthropic's API is degraded — which happens a few times a year — a Hermes instance without a fallback becomes completely non-functional. The &lt;code&gt;fallback&lt;/code&gt; key configures an alternative provider that Hermes switches to automatically when the primary provider returns errors:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml&lt;/span&gt;
&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

&lt;span class="na"&gt;fallback&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;openai/gpt-4o&lt;/span&gt;
  &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;OPENAI_API_KEY&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${OPENAI_API_KEY}"&lt;/span&gt;
  &lt;span class="na"&gt;trigger&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;on_error_codes&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;429&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;500&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;502&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;503&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;504&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;consecutive_failures&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;3&lt;/span&gt;            &lt;span class="c1"&gt;# Switch after 3 consecutive failures&lt;/span&gt;
  &lt;span class="na"&gt;recovery&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;check_interval_seconds&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;300&lt;/span&gt;        &lt;span class="c1"&gt;# Check primary provider every 5 minutes&lt;/span&gt;
    &lt;span class="na"&gt;return_after_successful_checks&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;2&lt;/span&gt;  &lt;span class="c1"&gt;# Return to primary after 2 successful health checks&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The fallback model does not need to match the primary model's capability tier exactly — it needs to be good enough to handle the tasks your cron jobs and automated workflows run while the primary provider is down. I use GPT-4o as the fallback for Sonnet because the capability overlap is high and the MCP tool calling behavior is similar enough that my existing workflows work without modification.&lt;/p&gt;

&lt;p&gt;One thing to watch: fallback models may have different tool calling output formats, especially for complex nested tool calls. If your downstream code parses Hermes's output programmatically, test it against the fallback model before relying on automatic switching in production.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pattern 11: Capability Filter Discipline
&lt;/h2&gt;

&lt;p&gt;The &lt;code&gt;include&lt;/code&gt; and &lt;code&gt;exclude&lt;/code&gt; keys apply at the server level, but there are two additional capability types you can filter that most documentation does not mention: &lt;code&gt;prompts&lt;/code&gt; and &lt;code&gt;resources&lt;/code&gt;. MCP servers can expose three capability categories — tools, prompts, and resources — and Hermes enables all three by default:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml&lt;/span&gt;
&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;github&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-github"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;GITHUB_PERSONAL_ACCESS_TOKEN&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${GITHUB_TOKEN}"&lt;/span&gt;

    &lt;span class="c1"&gt;# Tool capability filter (whitelist)&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_issues&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;get_issue&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_issue&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;add_issue_comment&lt;/span&gt;

    &lt;span class="c1"&gt;# Explicitly disable prompt and resource capabilities&lt;/span&gt;
    &lt;span class="c1"&gt;# These add unnecessary context overhead in tool-only workflows&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="na"&gt;filesystem&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-filesystem@1.9.2"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/Users/yourname/projects"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;      &lt;span class="c1"&gt;# No prompt templates needed — we use the top-level systemPrompt&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;     &lt;span class="c1"&gt;# Keep resource access for file content fetching&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Disabling unused capability types reduces the size of the MCP capability advertisement that Hermes sends to the model at the start of each conversation. In a five-server setup, a full capability advertisement can run to 4,000-6,000 tokens before the user has said a word. Turning off &lt;code&gt;prompts&lt;/code&gt; and &lt;code&gt;resources&lt;/code&gt; on servers where you only need tools cuts this by 30-50%.&lt;/p&gt;

&lt;p&gt;The &lt;code&gt;exclude&lt;/code&gt; key is the alternative to &lt;code&gt;include&lt;/code&gt; when you want most tools but need to block specific ones:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;github&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-github"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;GITHUB_PERSONAL_ACCESS_TOKEN&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${GITHUB_TOKEN}"&lt;/span&gt;
    &lt;span class="na"&gt;exclude&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;delete_repository&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_repository&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;delete_branch&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;force_push&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Use &lt;code&gt;include&lt;/code&gt; when you want a small, well-defined set of tools (fewer than 10). Use &lt;code&gt;exclude&lt;/code&gt; when you want most tools but need to block specific destructive operations. Never use both on the same server — if you specify both &lt;code&gt;include&lt;/code&gt; and &lt;code&gt;exclude&lt;/code&gt;, Hermes v0.13.0 applies &lt;code&gt;include&lt;/code&gt; first and ignores &lt;code&gt;exclude&lt;/code&gt;. This behavior may change in future versions.&lt;/p&gt;

&lt;h2&gt;
  
  
  Pattern 12: Production Diagnostics
&lt;/h2&gt;

&lt;p&gt;When something goes wrong in production — a tool call hangs, a cron job fails, the dual-stack produces unexpected results — these are the diagnostic commands I run in order:&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Step 1: Full doctor check&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes doctor --verbose
# The --verbose flag checks MCP server reachability individually
# Output includes per-server connection test results
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Step 2: List connected tools&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes tools list --mcp
# Shows all tools currently registered from all connected MCP servers
# With --mcp flag, groups by server and shows server health status
# Example output:
#
# [mcp:filesystem] HEALTHY (7 tools)
#   read_file, write_file, list_directory, create_directory,
#   move_file, search_files, get_file_info
#
# [mcp:github] HEALTHY (4 tools, 2 excluded)
#   list_issues, get_issue, create_issue, add_issue_comment
#
# [mcp:slow-api] CIRCUIT_OPEN (circuit opened 3m ago, recovery in 57s)
#   (no tools available — circuit breaker active)
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Step 3: Inspect recent tool call logs&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes logs --last 50 --format json | jq '.[] | select(.type == "tool_call")'
# Shows the last 50 log entries filtered to tool calls only
# Each entry includes: timestamp, tool_name, server, duration_ms, status, error (if any)
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Step 4: Replay a failed task with debug logging&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes run --task "your failed task description"   --debug   --log-file /tmp/hermes-debug-$(date +%Y%m%d-%H%M%S).json
# Runs the task with full tool call tracing enabled
# Writes structured log to /tmp/ for inspection
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Step 5: Test a specific MCP server connection in isolation&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes mcp test --server github
# Runs the connection handshake for a single MCP server
# Reports capability negotiation, tool list, and a test tool call
# Useful for isolating whether a failure is in Hermes itself or the MCP server
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Step 6: Cron job inspection&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;hermes cron logs --job daily-digest --last 10
# Shows the last 10 runs of a specific cron job
# Includes task output, step count, duration, and failure reason if applicable
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The structured JSON log format (Pattern 12, step 3) is essential for debugging failures that are intermittent or time-sensitive. I pipe these logs to a simple monitoring script that alerts via Telegram when error rates exceed a threshold. The log format is stable across Hermes patch versions — the fields &lt;code&gt;type&lt;/code&gt;, &lt;code&gt;tool_name&lt;/code&gt;, &lt;code&gt;server&lt;/code&gt;, &lt;code&gt;duration_ms&lt;/code&gt;, and &lt;code&gt;status&lt;/code&gt; are documented in the v0.13.0 changelog as stable public API.&lt;/p&gt;

&lt;h2&gt;
  
  
  Full Production Config Reference
&lt;/h2&gt;

&lt;p&gt;Here is the complete &lt;code&gt;config.yaml&lt;/code&gt; that combines all 12 patterns into a single production-ready file. This is my actual config, sanitized for sharing:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ~/.hermes/config.yaml&lt;/span&gt;
&lt;span class="c1"&gt;# Hermes v0.13.0 — Full production config&lt;/span&gt;
&lt;span class="c1"&gt;# Last updated: 2026-05-16&lt;/span&gt;

&lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic/claude-sonnet-4-6&lt;/span&gt;

&lt;span class="na"&gt;systemPrompt&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
  &lt;span class="s"&gt;You are a senior development orchestration agent. You plan and execute&lt;/span&gt;
  &lt;span class="s"&gt;multi-step development workflows using your available tools. You do not&lt;/span&gt;
  &lt;span class="s"&gt;write code directly — delegate code generation to the claude_code tool.&lt;/span&gt;

  &lt;span class="s"&gt;Behavioral rules:&lt;/span&gt;
  &lt;span class="s"&gt;- Always read the current git status before modifying files&lt;/span&gt;
  &lt;span class="s"&gt;- Always run tests after modifying code (use bash tool to run npm test)&lt;/span&gt;
  &lt;span class="s"&gt;- Always commit changes to a feature branch, never directly to main&lt;/span&gt;
  &lt;span class="s"&gt;- Prefer reading documentation before making architectural decisions&lt;/span&gt;
  &lt;span class="s"&gt;- Summarize what you did at the end of every task&lt;/span&gt;

&lt;span class="na"&gt;models&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;router&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;provider&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude-haiku-4-5-20251001&lt;/span&gt;
    &lt;span class="na"&gt;temperature&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0.0&lt;/span&gt;
    &lt;span class="na"&gt;use_for&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;task_classification&lt;/span&gt;
  &lt;span class="na"&gt;reasoner&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;provider&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude-opus-4-7&lt;/span&gt;
    &lt;span class="na"&gt;temperature&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0.3&lt;/span&gt;
    &lt;span class="na"&gt;use_for&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;complex_planning&lt;/span&gt;
    &lt;span class="na"&gt;max_tokens&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;8192&lt;/span&gt;
  &lt;span class="na"&gt;summarizer&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;provider&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;anthropic&lt;/span&gt;
    &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude-haiku-4-5-20251001&lt;/span&gt;
    &lt;span class="na"&gt;temperature&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0.0&lt;/span&gt;
    &lt;span class="na"&gt;use_for&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;result_summarization&lt;/span&gt;

&lt;span class="na"&gt;fallback&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;model&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;openai/gpt-4o&lt;/span&gt;
  &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;OPENAI_API_KEY&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${OPENAI_API_KEY}"&lt;/span&gt;
  &lt;span class="na"&gt;trigger&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;on_error_codes&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;429&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;500&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;502&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;503&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;504&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;consecutive_failures&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;3&lt;/span&gt;
  &lt;span class="na"&gt;recovery&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;check_interval_seconds&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;300&lt;/span&gt;
    &lt;span class="na"&gt;return_after_successful_checks&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;2&lt;/span&gt;

&lt;span class="na"&gt;routing&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;classify_tasks&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="na"&gt;auto_route_complex&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="na"&gt;complexity_threshold&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;8&lt;/span&gt;

&lt;span class="na"&gt;mcpServers&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;filesystem&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-filesystem@1.9.2"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;/Users/yourname/projects"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="na"&gt;git&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-git@0.6.2"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;GIT_AUTHOR_NAME&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Hermes&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;Agent"&lt;/span&gt;
      &lt;span class="na"&gt;GIT_AUTHOR_EMAIL&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;hermes@yourproject.local"&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="na"&gt;github&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-github"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;GITHUB_PERSONAL_ACCESS_TOKEN&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${GITHUB_TOKEN}"&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_issues&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;get_issue&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_issue&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;add_issue_comment&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_pull_requests&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_pull_request&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="na"&gt;postgres&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npx&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;-y"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;@modelcontextprotocol/server-postgres"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;${DATABASE_URL}"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;query&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;list_tables&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;describe_table&lt;/span&gt;
    &lt;span class="na"&gt;use_gateway&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;timeout_seconds&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;60&lt;/span&gt;
      &lt;span class="na"&gt;retry&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;max_attempts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;2&lt;/span&gt;
        &lt;span class="na"&gt;backoff&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;exponential&lt;/span&gt;
        &lt;span class="na"&gt;initial_delay_ms&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;500&lt;/span&gt;
      &lt;span class="na"&gt;circuit_breaker&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;failure_threshold&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;3&lt;/span&gt;
        &lt;span class="na"&gt;recovery_timeout_s&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;120&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;prompts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="na"&gt;claude_code&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;claude&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;mcp"&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;serve"&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;
    &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Claude&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;Code&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;—&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;use&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;for&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;all&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;code&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;generation,&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;TypeScript,&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;React,&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;and&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;file&lt;/span&gt;&lt;span class="nv"&gt; &lt;/span&gt;&lt;span class="s"&gt;edits"&lt;/span&gt;
    &lt;span class="na"&gt;include&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;edit_file&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;create_file&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;read_file&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;run_bash_command&lt;/span&gt;

&lt;span class="na"&gt;serve&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;transport&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;stdio&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;hermes-orchestrator&lt;/span&gt;
  &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
    &lt;span class="s"&gt;Hermes multi-step development orchestrator. Accepts natural language task&lt;/span&gt;
    &lt;span class="s"&gt;descriptions and executes them autonomously using filesystem, git, GitHub,&lt;/span&gt;
    &lt;span class="s"&gt;Postgres, and Claude Code tools.&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  What the Dual-Stack Changes Day-to-Day
&lt;/h2&gt;

&lt;p&gt;After running this setup for three months, the practical difference is that I spend significantly less time context-switching between tools. A task like "implement the subscription cancellation flow, write the API route, the client component, and the email notification, then open a PR" — which previously required me to coordinate multiple Claude Code sessions, manually run git commands, and interact with the GitHub UI — now runs end-to-end in a single Hermes invocation. Claude Code handles the code. Hermes handles the coordination.&lt;/p&gt;

&lt;p&gt;The failure modes are real but manageable. MCP server startup time adds 2-5 seconds to the first tool call in a new session — this is the child process startup latency. In interactive sessions this is invisible. In cron jobs it is worth noting in your timeout calculations. The circuit breaker (Pattern 8) has saved me from cascading failures twice when my internal API was down. Without it, those cron jobs would have hung for their full timeout duration on every scheduled run until I manually intervened.&lt;/p&gt;

&lt;p&gt;Version pinning (Pattern 1, the &lt;code&gt;@1.9.2&lt;/code&gt; syntax) is not optional in production. MCP server packages ship frequently and minor versions occasionally contain breaking changes in tool output format. Pin your versions, test before upgrading, and keep a note of which version is in production. I learned this the hard way when &lt;code&gt;server-filesystem&lt;/code&gt; changed the &lt;code&gt;list_directory&lt;/code&gt; output format in a patch version and broke a downstream script that was parsing the output.&lt;/p&gt;

&lt;h2&gt;
  
  
  Run &lt;code&gt;hermes doctor&lt;/code&gt; as part of your deployment verification. If your deployment process changes environment variables or Node versions, a doctor check immediately after deploy catches configuration problems before they cause silent failures in production workflows. I have it in my post-deploy script alongside the standard HTTP health check.
&lt;/h2&gt;

&lt;p&gt;&lt;em&gt;Originally published at &lt;a href="https://wowhow.cloud/blogs/hermes-agent-tool-gateway-claude-code-mcp-12-patterns-2026" rel="noopener noreferrer"&gt;wowhow.cloud&lt;/a&gt;&lt;/em&gt;&lt;/p&gt;

</description>
      <category>hermestool</category>
      <category>hermesmcp</category>
      <category>claudecode</category>
      <category>hermesagent</category>
    </item>
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