Stop AI Agents from Guessing API Routes: Crazyrouter llms.txt Endpoint Guide

#api #ai #agents #documentation

Stop AI Agents from Guessing API Routes: Crazyrouter `llms.txt` Endpoint Guide

When an AI agent writes API code, the most expensive bug is often not a typo. It is an endpoint mismatch.

A model might support Chat Completions, Responses, Claude Messages, Gemini native calls, image generation, video generation, or audio APIs. If the AI guesses the route from memory, the generated code may look reasonable while still being wrong.

Crazyrouter's llms.txt helps prevent that.

https://docs.crazyrouter.com/llms.txt

The user-facing guide is here:

https://docs.crazyrouter.com/llms-guide?utm_source=devto&utm_medium=article&utm_campaign=llms_txt_docs

The core idea

Before generating code, tell the AI to read the docs entry point and match the model's endpoint type to the correct documentation page.

Use this prompt:

Read https://docs.crazyrouter.com/llms.txt first.
Use Crazyrouter's official docs to choose the correct endpoint.
Do not invent model names, prices, billing modes, or routes from memory.
Generate code only after matching the model to the correct endpoint type.

Common endpoint mappings

Here are the important mappings AI tools should not guess:

Use case	Crazyrouter endpoint
OpenAI Chat Completions	`POST /v1/chat/completions`
OpenAI Responses	`POST /v1/responses`
Anthropic Messages	`POST /v1/messages`
Gemini native	`POST /v1beta/models/{model}:generateContent`
Image generation	`POST /v1/images/generations`
Image editing	`POST /v1/images/edits`
OpenAI-style video	`POST /v1/video/generations` or `POST /v1/videos`
Unified video	`POST /v1/video/create` and `GET /v1/video/query`
Text-to-speech	`POST /v1/audio/speech`
Speech-to-text	`POST /v1/audio/transcriptions`

Base URL details

For OpenAI-compatible SDKs:

https://cn.crazyrouter.com/v1

For raw HTTP Chat Completions:

https://cn.crazyrouter.com/v1/chat/completions

For Anthropic-native clients, use the root domain expected by the client rather than manually appending /v1 in the wrong place.

This is the kind of detail that llms.txt is designed to surface before the AI writes code.

Pricing and model availability

Do not ask an AI model to rely on memory for model names or prices.

Use:

https://crazyrouter.com/pricing

For machine-readable pricing data:

https://crazyrouter.com/api/pricing?lang=en

For the exact models available to a specific API key:

curl https://cn.crazyrouter.com/v1/models \
  -H "Authorization: Bearer YOUR_API_KEY"

Use YOUR_API_KEY in shared prompts. Do not paste real keys into public chats or untrusted tools.

Example: better agent instruction

Bad prompt:

Write code to call a Crazyrouter model.

Better prompt:

Read https://docs.crazyrouter.com/llms.txt first.
My task is to call [MODEL_NAME] from Node.js.
Check which endpoint type applies, then write runnable code.
Use YOUR_API_KEY as the placeholder.
If the model or endpoint is uncertain, tell me to verify it on https://crazyrouter.com/pricing or GET /v1/models.