uignore — a .gitignore for AI coding tools

Anurag Patel — Sat, 21 Mar 2026 16:51:13 +0000

AI coding tools are incredibly useful. They can read your codebase, understand context across dozens of files, and make changes in seconds.

They can also read your .env file. Your secrets/ directory.
Your SSH keys. Your AWS credentials.

Not because they're malicious — but because nothing stops them by default.

I built uignore to fix this.

What is uignore?

uignore gives you a single .uignore file — same syntax as .gitignore — that blocks file access across all supported AI tools simultaneously.

  gitignore
  # .uignore
  secrets/
  .env
  .env.*
  *.pem
  *.key

Add a path once. Claude Code, Gemini CLI, Cursor, and Windsurf all respect it automatically.

How it works

Each AI tool has a native hook system:


  ┌─────────────┬────────────────┬─────────────────┐
  │    Tool     │      Hook      │ Block mechanism │
  ├─────────────┼────────────────┼─────────────────┤
  │ Claude Code │ PreToolUse     │ exit code 2     │
  ├─────────────┼────────────────┼─────────────────┤
  │ Gemini CLI  │ BeforeTool     │ exit code 2     │
  ├─────────────┼────────────────┼─────────────────┤
  │ Cursor      │ beforeReadFile │ exit code 2     │
  ├─────────────┼────────────────┼─────────────────┤
  │ Windsurf    │ pre_read_code  │ exit code 2     │
  └─────────────┴────────────────┴─────────────────┘

uignore registers a hook with each tool. Before every file read or write, the hook resolves the target path against your .uignore rules.
If it matches — the operation is blocked. The file content never reaches the model.

Getting started

No global install required:

 npx @ottoai/uignore init     # creates a .uignore template
 npx @ottoai/uignore install  # registers hooks for all tools

Then commit to git:

  git add .uignore .claude/settings.json .gemini/settings.json \
          .cursor/hooks.json .windsurf/hooks.json
  git commit -m "chore: add uignore"

Your whole team now has the same protection automatically.
No per-developer setup required.

Syntax
uignore follows .gitignore conventions:

  # Block a directory
  secrets/

  # Block specific file types
  *.pem
  *.key

  # Block .env and all variants
  .env
  .env.*

  # Block everything except README
  *.md
  !README.md

Hierarchical .uignore files are supported — place one in any subdirectory for subtree-specific rules. A global ~/.uignore applies personal rules across every project.

CLI


  uignore check secrets/apikey.txt   # test if a file would be blocked
  uignore list                        # show all active rules
  uignore diff                        # show which tracked files are blocked
  uignore doctor                      # diagnose config problems
  uignore add *.pem                   # add a pattern
  uignore remove *.pem                # remove a pattern

Open source

MIT licensed. Contributions welcome.

GitHub: https://github.com/otto-open-labs/uignore
npm: https://npmjs.com/package/@ottoai/uignore

If you use an AI tool that isn't supported yet, PRs are open.

Forem: Anurag Patel

uignore — a .gitignore for AI coding tools

What is uignore?

How it works

Getting started

CLI

Open source