Claude API Proxy

A production-ready Claude API proxy server that converts Claude API requests to OpenAI-compatible format. Extremely simple to use - just set environment variables and run.

Features

• 🔄 Protocol Conversion: Complete Claude API to OpenAI API format conversion
• 🚀 High Performance: Async FastAPI with connection pooling
• 📡 Streaming Support: Real-time Server-Sent Events streaming
• 🎯 Smart Model Mapping: Automatic model routing (Haiku→Small, Sonnet/Opus→Big)
• 🐳 Docker Ready: Easy deployment with Docker/Docker Compose
• 🔍 Observable: Health checks, logging, and error handling
• ⚡ Zero Configuration: Works with any OpenAI-compatible API

Quick Start

pip install claude-proxy

# Option 1: Fixed API Key Mode (recommended for single user)
export OPENAI_API_KEY=sk-your-api-key
export OPENAI_BASE_URL=https://api.openai.com/v1
claude-proxy

# Option 2: Passthrough Mode (for multi-user scenarios)  
export OPENAI_BASE_URL=https://api.openai.com/v1
# Don't set OPENAI_API_KEY - proxy will forward each client's API key
claude-proxy

Production Deployment

🐳 Docker (Recommended for Production)

The easiest and most reliable way to run in production:

# 1. Set environment variables (Fixed API Key mode)
export OPENAI_API_KEY=sk-your-production-key
export OPENAI_BASE_URL=https://api.openai.com/v1
export CLAUDE_PROXY_AUTH_KEY=sk-your-own-key

# Or for Passthrough mode, don't set OPENAI_API_KEY and CLAUDE_PROXY_AUTH_KEY:
# export OPENAI_BASE_URL=https://api.openai.com/v1

# 2. Start with docker-compose
docker-compose up -d

# Or build and run manually
docker build -t claude-proxy .
docker run -p 8085:8085 --env-file .env claude-proxy

⚡ Manual Production Setup

For environments where Docker isn't available:

# Install with production dependencies (includes Gunicorn)
pip install claude-proxy[production]

# Set your configuration (Fixed API Key mode)
export OPENAI_API_KEY=sk-your-production-key
export OPENAI_BASE_URL=https://api.openai.com/v1
export CLAUDE_PROXY_AUTH_KEY=sk-your-own-key

# Or for Passthrough mode, don't set OPENAI_API_KEY and CLAUDE_PROXY_AUTH_KEY

# Run with Gunicorn + Uvicorn workers
gunicorn claude_proxy.main:app \
  --workers 4 \
  --worker-class uvicorn.workers.UvicornWorker \
  --bind 0.0.0.0:8085 \
  --access-logfile - \
  --error-logfile -

🎯 Production Features

• Multi-process: 4 Gunicorn workers with Uvicorn for high concurrency
• Health checks: Built-in monitoring endpoint
• Security: Non-root user, minimal attack surface
• Resource limits: Configurable CPU/memory constraints
• Auto-restart: Automatic recovery from failures

API Endpoints

• POST /v1/messages - Chat completions (Claude API compatible)
• POST /v1/messages/count_tokens - Token counting
• GET /health - Health check
• GET /test-connection - Test target API connectivity
• GET / - Service information

That's it! The proxy is ready to use with Claude Code.

Supported Providers

OpenAI

export OPENAI_BASE_URL=https://api.openai.com/v1
export CLAUDE_PROXY_BIG_MODEL=gpt-4o
export CLAUDE_PROXY_SMALL_MODEL=gpt-4o-mini
claude-proxy

Alibaba Cloud DashScope

export OPENAI_BASE_URL=https://dashscope.aliyuncs.com/compatible-mode/v1
export CLAUDE_PROXY_BIG_MODEL=qwen3-coder-plus
export CLAUDE_PROXY_SMALL_MODEL=qwen3-coder-flash
claude-proxy

Azure OpenAI

export OPENAI_BASE_URL=https://your-resource.openai.azure.com/openai/deployments/your-deployment
export CLAUDE_PROXY_BIG_MODEL=gpt-4
export CLAUDE_PROXY_SMALL_MODEL=gpt-35-turbo
claude-proxy

Local Ollama

export OPENAI_BASE_URL=http://localhost:11434/v1
export CLAUDE_PROXY_BIG_MODEL=llama3.1:70b
export CLAUDE_PROXY_SMALL_MODEL=llama3.1:8b
claude-proxy

Environment Variables

• OPENAI_API_KEY - API key for your target provider (optional - enables Fixed API Key mode if set)
• OPENAI_BASE_URL - API endpoint URL (default: https://api.openai.com/v1)

Mode Selection:

• If OPENAI_API_KEY is set: Fixed API Key mode - proxy uses this key for all requests

• If OPENAI_API_KEY is NOT set: Passthrough mode - proxy forwards each client's API key

• CLAUDE_PROXY_BIG_MODEL - Model for Claude Sonnet/Opus requests (default: gpt-4o)

• CLAUDE_PROXY_SMALL_MODEL - Model for Claude Haiku requests (default: gpt-4o-mini)

• CLAUDE_PROXY_HOST - Server host (default: 0.0.0.0)

• CLAUDE_PROXY_PORT - Server port (default: 8085)

• CLAUDE_PROXY_LOG_LEVEL - Logging level (default: INFO)

• CLAUDE_PROXY_REQUEST_TIMEOUT - Request timeout in seconds (default: 90)

• CLAUDE_PROXY_AUTH_KEY - Required API key for proxy access validation (optional, only for Fixed API Key mode)

Authentication & Security

Fixed API Key Mode

• Recommended: Set CLAUDE_PROXY_AUTH_KEY to validate client access
• All requests to target provider use the same OPENAI_API_KEY
• Clients provide any API key to the proxy (validated against CLAUDE_PROXY_AUTH_KEY)

Passthrough Mode

• Don't set CLAUDE_PROXY_AUTH_KEY - each client uses their own API key
• Client's API key is forwarded directly to the target provider
• No additional proxy-level authentication needed

Model Mapping

The proxy automatically maps Claude models to your configured models:

Claude Request	Environment Variable	Default Value
claude-3-haiku*	CLAUDE_PROXY_SMALL_MODEL	gpt-4o-mini
claude-3-sonnet*	CLAUDE_PROXY_BIG_MODEL	gpt-4o
claude-3-opus*	CLAUDE_PROXY_BIG_MODEL	gpt-4o
claude-sonnet-4*	CLAUDE_PROXY_BIG_MODEL	gpt-4o

Configuration Examples

Example .env for OpenAI

OPENAI_BASE_URL=https://api.openai.com/v1
CLAUDE_PROXY_BIG_MODEL=gpt-4o
CLAUDE_PROXY_SMALL_MODEL=gpt-4o-mini
CLAUDE_PROXY_LOG_LEVEL=INFO

Example .env for DashScope

OPENAI_BASE_URL=https://dashscope.aliyuncs.com/compatible-mode/v1  
CLAUDE_PROXY_BIG_MODEL=qwen3-coder-plus
CLAUDE_PROXY_SMALL_MODEL=qwen3-coder-flash
CLAUDE_PROXY_LOG_LEVEL=INFO

Example .env for Fixed API Key Mode

OPENAI_API_KEY=sk-your-production-key # enables Fixed API Key Mode
CLAUDE_PROXY_AUTH_KEY=sk-your-own-key # optional
OPENAI_BASE_URL=https://api.openai.com/v1
CLAUDE_PROXY_BIG_MODEL=gpt-4o
CLAUDE_PROXY_SMALL_MODEL=gpt-4o-mini
CLAUDE_PROXY_LOG_LEVEL=INFO

Development

Setup Development Environment

# Clone repository
git clone <repository-url>
cd claude-proxy

# Install with uv
uv sync

# Set development configuration
cp .env.example .env
vim .env

# Run in development
uv run claude-proxy

Running Tests

# Run all tests
uv run pytest

# Run with coverage
uv run pytest --cov=claude_proxy --cov-report=html

# Test specific functionality
uv run pytest -v

Code Quality

# Format code
uv run black .

# Lint code  
uv run ruff check .

# Type checking
uv run mypy .

Troubleshooting

Connection Issues

# Test target API directly
curl -X POST "$OPENAI_BASE_URL/chat/completions" \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"gpt-3.5-turbo","messages":[{"role":"user","content":"test"}],"max_tokens":5}'

# Test proxy health
curl http://localhost:8085/health

# Test proxy connection  
curl http://localhost:8085/test-connection

Common Issues

• 404 Not Found: Check your OPENAI_BASE_URL and model names
• 401 Unauthorized: Verify your OPENAI_API_KEY is valid
• Model not found: Ensure CLAUDE_PROXY_BIG_MODEL and CLAUDE_PROXY_SMALL_MODEL exist in your provider

License

MIT License - see LICENSE file for details.