How I Cut AI API Costs by 45x With a Simple Routing Proxy

BernardinoGM — Wed, 25 Mar 2026 23:43:50 +0000

Last week I ran a simple test. I sent "Say hi" to two different AI APIs.

Claude/OpenAI cost: $0.000179
Through my routing proxy: $0.000004

Same response quality. 45x price difference.

The insight

I analyzed a month of API traffic from a production app. Here's what I found:

72% of requests were simple tasks: classification, extraction, summarization, translation
18% were medium: multi-step analysis, moderate code generation
10% were genuinely hard: complex reasoning, system design, novel code

The simple tasks ran identically on DeepSeek V4 at $0.14/M tokens. We were paying Claude $15/M for the same work. That's a 100x markup on commodity tasks.

The solution

I built an OpenAI-compatible proxy that classifies each request and routes to the cheapest capable model:

Complexity	Model	Cost/M tokens
Simple (~70%)	DeepSeek V4	$0.14 / $0.28
Medium (~20%)	DeepSeek R1	$0.55 / $2.19
Hard (~10%)	Claude Sonnet	$3.00 / $15.00

The classifier itself uses DeepSeek (cost: ~$0.001 per classification). If a cheap model fails, it auto-fallbacks to the next tier.

How to use it

Change one line. Everything else stays the same:

from openai import OpenAI

# Before
client = OpenAI(
    api_key="sk-your-openai-key",
    base_url="https://api.openai.com/v1"
)

# After
client = OpenAI(
    api_key="sk-bridge-your-key",
    base_url="https://ai-bridge-router-et30.onrender.com/v1"
)

# This code doesn't change at all
response = client.chat.completions.create(
    model="auto",
    messages=[{"role": "user", "content": "Classify this as positive or negative: I love this product"}],
    stream=True
)

The response includes routing metadata:

"_bridge": {
    "complexity": "simple",
    "model": "DeepSeek V4",
    "cost_usd": 0.000004,
    "benchmark_usd": 0.000179
}

The math at scale

For a team spending $3,000/month on AI APIs:

70% simple tasks: $3K × 0.7 × ($0.21/$5.00) = $88
20% medium: $3K × 0.2 × ($1.37/$5.00) = $164
10% hard: $3K × 0.1 × ($9.00/$5.00) = $540
Total: ~$792/month instead of $3,000

That's a 74% reduction, or $26,496 saved per year.

Try it

Free tier available (50K tokens/day, no credit card):

Get a free API key →

Or self-host: GitHub repo

Technical details

Stack: Python, FastAPI, httpx async, SQLite
Streaming: Full SSE support, converts Anthropic format to OpenAI format on the fly
Classification: LLM-based (DeepSeek classifies requests) with keyword fallback
Fallback: Auto-escalates if cheap model returns error

The entire router is a single Python file. MIT licensed.

If you're spending $500+/month on AI APIs, the routing proxy probably pays for itself in the first week. Try it free or self-host from GitHub.