ChunkBack lets you test your apps with LLM provider endpoints without having to pay for the providers.
ChunkBack is a simple express server that emulates the response input and output of popular LLM providers, currently Gemini, Anthropic and OpenAI. Chunkback accepts a custom prompt language called CBPL that lets you customize the response to your applications.
npx chunkback@latest
Then run in your terminal:
curl -X POST http://localhost:5654/v1/chat/completions \
-H "Content-Type: application/json" \
-d '{
"model": "swag",
"messages": [
{"role": "user", "content": "SAY \"First message\"\nCHUNKSIZE 3\nCHUNKLATENCY 50\nSAY \"Second message\""}
]
}'
- Deterministic API response - You always will get back the same content you put in
- Saves money - When testing your application, you can stub out your LLM calls with this
- Open Source - You can see the code right there!
- No extra services dependencies - There's no DB no Redis no nothing, just server code
See CONTRIBUTING.md for:
MIT License - see LICENSE for details.
This project was built with the assistance of autogenerated coding libraries - most code was reviewed by a human (painstakingly). This README.md was handwritten, and should be kep that way.