FreeBrain AI API Documentation

Overview

FreeBrain provides an API gateway for calling AI models. Start with a FreeBrain API key and the base URL https://api.thefreebrain.com/v1 for an OpenAI-compatible client. Supported endpoints and parameters depend on the model you select in the model catalog.

Start here

• Make your first API request: create a key, choose a chat model, and call it with cURL or Python.
• Troubleshoot API errors: check authentication, base URLs, model access, rate limits, and streaming.
• Compare models and pricing: check each model's endpoint and billing unit before integrating it.
• Read the FAQ: billing, prices, keys, endpoints and the tools you can use.

Use FreeBrain in your tools

• Claude Code: one command or your settings file, with Opus, Sonnet and Haiku mapped to FreeBrain models.
• Codex: add FreeBrain as a provider in config.toml and run Codex through the Responses API.
• CC Switch: import FreeBrain for Claude Code or Codex in one click.
• Cherry Studio: add FreeBrain as a provider and chat with Claude and GPT models.

Use FreeBrain in your code

• Connect an OpenAI-compatible app: check connection settings and features before switching traffic.
• Use the Python OpenAI SDK: run text and streaming examples with error handling.
• Use the Node.js OpenAI SDK: configure JavaScript and read streaming responses.

AI Model APIs

These pages describe model API formats. Use the format supported by your chosen model; an endpoint in the reference does not imply that every model or account supports it.