Claude Code but with OpenAI Models 🧙‍♂️🔄 ¯\(ツ)/¯

Use Claude Code with OpenAI Models 🤝

A proxy server that lets you use Claude Code with OpenAI models like GPT-4o / gpt-4.5 and o3-mini. 🌉

Quick Start ⚡

Clone this repository:

git clone https://github.com/1rgs/claude-code-openai.git
cd claude-code-openai

Install UV:

 curl -LsSf https://astral.sh/uv/install.sh | sh

Configure your API keys: Create a .env file with:

OPENAI_API_KEY=your-openai-key
# Optional: customize which models are used
# BIG_MODEL=gpt-4o
# SMALL_MODEL=gpt-4o-mini

Start the proxy server:

uv run uvicorn server:app --host 0.0.0.0 --port 8082

Install Claude Code (if you haven't already):
```
npm install -g @anthropic-ai/claude-code
```

Connect to your proxy:

ANTHROPIC_BASE_URL=http://localhost:8082 claude

That's it! Your Claude Code client will now use OpenAI models through the proxy. 🎯

The proxy automatically maps Claude models to OpenAI models:

Claude Model	OpenAI Model
haiku	gpt-4o-mini (default)
sonnet	gpt-4o (default)

You can customize which OpenAI models are used via environment variables:

BIG_MODEL: The OpenAI model to use for Claude Sonnet models (default: "gpt-4o")
SMALL_MODEL: The OpenAI model to use for Claude Haiku models (default: "gpt-4o-mini")

Add these to your .env file to customize:

OPENAI_API_KEY=your-openai-key
BIG_MODEL=gpt-4o
SMALL_MODEL=gpt-4o-mini

Or set them directly when running the server:

BIG_MODEL=gpt-4o SMALL_MODEL=gpt-4o-mini uv run uvicorn server:app --host 0.0.0.0 --port 8082

This proxy works by:

The proxy handles both streaming and non-streaming responses, maintaining compatibility with all Claude clients. 🌊

Contributions are welcome! Please feel free to submit a Pull Request. 🎁