Claude Code OpenAI API Wrapper

An OpenAI API-compatible wrapper for Claude Code, allowing you to use Claude Code with any OpenAI client library. Now powered by the official Claude Code Python SDK with enhanced authentication and features.

Status

🎉 Production Ready - All core features working and tested:

• ✅ Chat completions endpoint with official Claude Code Python SDK
• ✅ Streaming and non-streaming responses
• ✅ Full OpenAI SDK compatibility
• ✅ Multi-provider authentication (API key, Bedrock, Vertex AI, CLI auth)
• ✅ System prompt support via SDK options
• ✅ Model selection support with validation
• ✅ Fast by default - Tools disabled for OpenAI compatibility (5-10x faster)
• ✅ Optional tool usage (Read, Write, Bash, etc.) when explicitly enabled
• ✅ Real-time cost and token tracking from SDK
• ✅ Session continuity with conversation history across requests 🆕
• ✅ Session management endpoints for full session control 🆕
• ✅ Health, auth status, and models endpoints
• ✅ Development mode with auto-reload

Features

🔥 Core API Compatibility

• OpenAI-compatible /v1/chat/completions endpoint
• Support for both streaming and non-streaming responses
• Compatible with OpenAI Python SDK and all OpenAI client libraries
• Automatic model validation and selection

🛠 Claude Code SDK Integration

• Official Claude Code Python SDK integration (v0.0.14)
• Real-time cost tracking - actual costs from SDK metadata
• Accurate token counting - input/output tokens from SDK
• Session management - proper session IDs and continuity
• Enhanced error handling with detailed authentication diagnostics

🔐 Multi-Provider Authentication

• Automatic detection of authentication method
• Claude CLI auth - works with existing claude auth setup
• Direct API key - ANTHROPIC_API_KEY environment variable
• AWS Bedrock - enterprise authentication with AWS credentials
• Google Vertex AI - GCP authentication support

⚡ Advanced Features

• System prompt support via SDK options
• Optional tool usage - Enable Claude Code tools (Read, Write, Bash, etc.) when needed
• Fast default mode - Tools disabled by default for OpenAI API compatibility
• Development mode with auto-reload (uvicorn --reload)
• Interactive API key protection - Optional security with auto-generated tokens
• Comprehensive logging and debugging capabilities

Quick Start

Get started in under 2 minutes:

# 1. Install Claude Code CLI (if not already installed)
npm install -g @anthropic-ai/claude-code

# 2. Authenticate (choose one method)
claude auth login  # Recommended for development
# OR set: export ANTHROPIC_API_KEY=your-api-key

# 3. Clone and setup the wrapper
git clone https://github.com/RichardAtCT/claude-code-openai-wrapper
cd claude-code-openai-wrapper
poetry install

# 4. Start the server
poetry run uvicorn main:app --reload --port 8000

# 5. Test it works
poetry run python test_endpoints.py

🎉 That's it! Your OpenAI-compatible Claude Code API is running on http://localhost:8000

Prerequisites

1. Claude Code CLI: Install Claude Code CLI

   # Install Claude Code (follow Anthropic's official guide)
   npm install -g @anthropic-ai/claude-code

2. Authentication: Choose one method:

   • Option A: Authenticate via CLI (Recommended for development)

     claude auth login

   • Option B: Set environment variable

     export ANTHROPIC_API_KEY=your-api-key

   • Option C: Use AWS Bedrock or Google Vertex AI (see Configuration section)

3. Python 3.10+: Required for the server

4. Poetry: For dependency management

   # Install Poetry (if not already installed)
   curl -sSL https://install.python-poetry.org | python3 -

Installation

1. Clone the repository:

   git clone https://github.com/RichardAtCT/claude-code-openai-wrapper
   cd claude-code-openai-wrapper

2. Install dependencies with Poetry:

   poetry install

   This will create a virtual environment and install all dependencies.

3. Configure environment:

   cp .env.example .env
   # Edit .env with your preferences

Configuration

Edit the .env file:

# Claude CLI path (usually just "claude")
CLAUDE_CLI_PATH=claude

# Optional API key for client authentication
# If not set, server will prompt for interactive API key protection on startup
# API_KEY=your-optional-api-key

# Server port
PORT=8000

# Timeout in milliseconds
MAX_TIMEOUT=600000

# CORS origins
CORS_ORIGINS=["*"]

🔐 API Security Configuration

The server supports interactive API key protection for secure remote access:

1. No API key set: Server prompts "Enable API key protection? (y/N)" on startup

   • Choose No (default): Server runs without authentication
   • Choose Yes: Server generates and displays a secure API key

2. Environment API key set: Uses the configured API_KEY without prompting

# Example: Interactive protection enabled
poetry run python main.py

# Output:
# ============================================================
# 🔐 API Endpoint Security Configuration
# ============================================================
# Would you like to protect your API endpoint with an API key?
# This adds a security layer when accessing your server remotely.
# 
# Enable API key protection? (y/N): y
# 
# 🔑 API Key Generated!
# ============================================================
# API Key: Xf8k2mN9-vLp3qR5_zA7bW1cE4dY6sT0uI
# ============================================================
# 📋 IMPORTANT: Save this key - you'll need it for API calls!
#    Example usage:
#    curl -H "Authorization: Bearer Xf8k2mN9-vLp3qR5_zA7bW1cE4dY6sT0uI" \
#         http://localhost:8000/v1/models
# ============================================================

Perfect for:

• 🏠 Local development - No authentication needed
• 🌐 Remote access - Secure with generated tokens
• 🔒 VPN/Tailscale - Add security layer for remote endpoints

Running the Server

1. Verify Claude Code is installed and working:

   claude --version
   claude --print --model claude-3-5-haiku-20241022 "Hello"  # Test with fastest model

2. Start the server:

   Development mode (recommended - auto-reloads on changes):

   poetry run uvicorn main:app --reload --port 8000

   Production mode:

   poetry run python main.py

   Port Options for production mode:

   • Default: Uses port 8000 (or PORT from .env)
   • If port is in use, automatically finds next available port
   • Specify custom port: poetry run python main.py 9000
   • Set in environment: PORT=9000 poetry run python main.py

Usage Examples

Using curl

# Basic chat completion (no auth)
curl -X POST http://localhost:8000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-3-5-sonnet-20241022",
    "messages": [
      {"role": "user", "content": "What is 2 + 2?"}
    ]
  }'

# With API key protection (when enabled)
curl -X POST http://localhost:8000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer your-generated-api-key" \
  -d '{
    "model": "claude-3-5-sonnet-20241022",
    "messages": [
      {"role": "user", "content": "Write a Python hello world script"}
    ],
    "stream": true
  }'

Using OpenAI Python SDK

from openai import OpenAI

# Configure client (automatically detects auth requirements)
client = OpenAI(
    base_url="http://localhost:8000/v1",
    api_key="your-api-key-if-required"  # Only needed if protection enabled
)

# Alternative: Let examples auto-detect authentication
# The wrapper's example files automatically check server auth status

# Basic chat completion
response = client.chat.completions.create(
    model="claude-3-5-sonnet-20241022",
    messages=[
        {"role": "system", "content": "You are a helpful assistant."},
        {"role": "user", "content": "What files are in the current directory?"}
    ]
)

print(response.choices[0].message.content)
# Output: Fast response without tool usage (default behavior)

# Enable tools when you need them (e.g., to read files)
response = client.chat.completions.create(
    model="claude-3-5-sonnet-20241022",
    messages=[
        {"role": "user", "content": "What files are in the current directory?"}
    ],
    extra_body={"enable_tools": True}  # Enable tools for file access
)
print(response.choices[0].message.content)
# Output: Claude will actually read your directory and list the files!

# Check real costs and tokens
print(f"Cost: ${response.usage.total_tokens * 0.000003:.6f}")  # Real cost tracking
print(f"Tokens: {response.usage.total_tokens} ({response.usage.prompt_tokens} + {response.usage.completion_tokens})")

# Streaming
stream = client.chat.completions.create(
    model="claude-3-5-sonnet-20241022",
    messages=[
        {"role": "user", "content": "Explain quantum computing"}
    ],
    stream=True
)

for chunk in stream:
    if chunk.choices[0].delta.content:
        print(chunk.choices[0].delta.content, end="")

Supported Models

• claude-sonnet-4-20250514 (Recommended)
• claude-opus-4-20250514
• claude-3-7-sonnet-20250219
• claude-3-5-sonnet-20241022
• claude-3-5-haiku-20241022

The model parameter is passed to Claude Code via the --model flag.

Session Continuity 🆕

The wrapper now supports session continuity, allowing you to maintain conversation context across multiple requests. This is a powerful feature that goes beyond the standard OpenAI API.

How It Works

• Stateless Mode (default): Each request is independent, just like the standard OpenAI API
• Session Mode: Include a session_id to maintain conversation history across requests

Using Sessions with OpenAI SDK

import openai

client = openai.OpenAI(
    base_url="http://localhost:8000/v1",
    api_key="not-needed"
)

# Start a conversation with session continuity
response1 = client.chat.completions.create(
    model="claude-3-5-sonnet-20241022",
    messages=[
        {"role": "user", "content": "Hello! My name is Alice and I'm learning Python."}
    ],
    extra_body={"session_id": "my-learning-session"}
)

# Continue the conversation - Claude remembers the context
response2 = client.chat.completions.create(
    model="claude-3-5-sonnet-20241022", 
    messages=[
        {"role": "user", "content": "What's my name and what am I learning?"}
    ],
    extra_body={"session_id": "my-learning-session"}  # Same session ID
)
# Claude will remember: "Your name is Alice and you're learning Python."

Using Sessions with curl

# First message (add -H "Authorization: Bearer your-key" if auth enabled)
curl -X POST http://localhost:8000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-3-5-sonnet-20241022",
    "messages": [{"role": "user", "content": "My favorite color is blue."}],
    "session_id": "my-session"
  }'

# Follow-up message - context is maintained
curl -X POST http://localhost:8000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-3-5-sonnet-20241022", 
    "messages": [{"role": "user", "content": "What's my favorite color?"}],
    "session_id": "my-session"
  }'

Session Management

The wrapper provides endpoints to manage active sessions:

• GET /v1/sessions - List all active sessions
• GET /v1/sessions/{session_id} - Get session details
• DELETE /v1/sessions/{session_id} - Delete a session
• GET /v1/sessions/stats - Get session statistics

# List active sessions
curl http://localhost:8000/v1/sessions

# Get session details
curl http://localhost:8000/v1/sessions/my-session

# Delete a session
curl -X DELETE http://localhost:8000/v1/sessions/my-session

Session Features

• Automatic Expiration: Sessions expire after 1 hour of inactivity
• Streaming Support: Session continuity works with both streaming and non-streaming requests
• Memory Persistence: Full conversation history is maintained within the session
• Efficient Storage: Only active sessions are kept in memory

Examples

See examples/session_continuity.py for comprehensive Python examples and examples/session_curl_example.sh for curl examples.

API Endpoints

Core Endpoints

• POST /v1/chat/completions - OpenAI-compatible chat completions (supports session_id)
• GET /v1/models - List available models
• GET /v1/auth/status - Check authentication status and configuration
• GET /health - Health check endpoint

Session Management Endpoints 🆕

• GET /v1/sessions - List all active sessions
• GET /v1/sessions/{session_id} - Get detailed session information
• DELETE /v1/sessions/{session_id} - Delete a specific session
• GET /v1/sessions/stats - Get session manager statistics

Limitations & Roadmap

🚫 Current Limitations

• Images in messages are converted to text placeholders
• Function calling not supported (tools work automatically based on prompts)
• OpenAI parameters not yet mapped: temperature, top_p, max_tokens, logit_bias, presence_penalty, frequency_penalty
• Multiple responses (n > 1) not supported

🛣 Planned Enhancements

• Tool configuration - allowed/disallowed tools endpoints
• OpenAI parameter mapping - temperature, top_p, max_tokens support
• Enhanced streaming - better chunk handling
• MCP integration - Model Context Protocol server support

✅ Recent Improvements

• ✅ SDK Integration: Official Python SDK replaces subprocess calls
• ✅ Real Metadata: Accurate costs and token counts from SDK
• ✅ Multi-auth: Support for CLI, API key, Bedrock, and Vertex AI authentication
• ✅ Session IDs: Proper session tracking and management
• ✅ System Prompts: Full support via SDK options
• ✅ Session Continuity: Conversation history across requests with session management

Troubleshooting

1. Claude CLI not found:

   # Check Claude is in PATH
   which claude
   # Update CLAUDE_CLI_PATH in .env if needed

2. Authentication errors:

   # Test authentication with fastest model
   claude --print --model claude-3-5-haiku-20241022 "Hello"
   # If this fails, re-authenticate if needed

3. Timeout errors:

   • Increase MAX_TIMEOUT in .env
   • Note: Claude Code can take time for complex requests

Testing

🧪 Quick Test Suite

Test all endpoints with a simple script:

# Make sure server is running first
poetry run python test_endpoints.py

📝 Basic Test Suite

Run the comprehensive test suite:

# Make sure server is running first  
poetry run python test_basic.py

# With API key protection enabled, set TEST_API_KEY:
TEST_API_KEY=your-generated-key poetry run python test_basic.py

The test suite automatically detects whether API key protection is enabled and provides helpful guidance for providing the necessary authentication.

🔍 Authentication Test

Check authentication status:

curl http://localhost:8000/v1/auth/status | python -m json.tool

⚙️ Development Tools

# Install development dependencies
poetry install --with dev

# Format code
poetry run black .

# Run full tests (when implemented)
poetry run pytest tests/

✅ Expected Results

All tests should show:

• 4/4 endpoint tests passing
• 4/4 basic tests passing
• Authentication method detected (claude_cli, anthropic, bedrock, or vertex)
• Real cost tracking (e.g., $0.001-0.005 per test call)
• Accurate token counts from SDK metadata

License

MIT License

Contributing

Contributions are welcome! Please open an issue or submit a pull request.