A universal LLM proxy that connects Claude Code to any language model provider

Production-ready LLM proxy server that converts requests from various LLM providers to Anthropic's Claude API format. Built with Go for high performance and reliability.

As simple as CCO_API_KEY="<openrouter key>" cco code and then selecting openrouter,qwen/qwen3-coder as model and voila

Inspired by Claude Code Router but rebuilt from the ground up to actually work reliably.

# Set your API key (works with any provider)
# This is the API key of the provider you want to use, can be any one of the supported providers
# Then in Claude Code you set the model with <provider>,<model name> e.g. openrouter,moonshotai/kimi-k2
export CCO_API_KEY="your-api-key-here"

# Start the router immediately - no config file needed!
# Although you can create a config if you want to store your API keys for all providers
cco start  # or claude-code-open start

# The API key will be used for whichever provider your model requests
# e.g., if you use "openrouter,anthropic/claude-sonnet-4" -> key goes to OpenRouter
# e.g., if you use "openai,gpt-4o" -> key goes to OpenAI

cco config generate  # or claude-code-open config generate

# config.yaml
host: 127.0.0.1
port: 6970
api_key: your-proxy-key  # Optional: protect the proxy

providers:
  - name: openrouter
    api_key: your-openrouter-api-key
    model_whitelist: ["claude", "gpt-4"]  # Optional: filter models
  - name: openai
    api_key: your-openai-api-key
  # ... etc

cco config init  # or claude-code-open config init

type Provider interface {
    Name() string
    SupportsStreaming() bool
    TransformRequest(request []byte) ([]byte, error)
    TransformResponse(response []byte) ([]byte, error)
    TransformStream(chunk []byte, state *StreamState) ([]byte, error)
    IsStreaming(headers map[string][]string) bool
    GetEndpoint() string
    SetAPIKey(key string)
}

# Server settings
host: 127.0.0.1
port: 6970
api_key: your-proxy-key-here  # Optional: protect proxy with authentication

# Provider configurations  
providers:
  # OpenRouter - Access to multiple models
  - name: openrouter
    api_key: your-openrouter-api-key
    # url: auto-populated from defaults
    # default_models: auto-populated with curated list
    model_whitelist: ["claude", "gpt-4"]  # Optional: filter models by pattern

  # OpenAI - Direct GPT access
  - name: openai
    api_key: your-openai-api-key
    # Automatically configured with GPT-4, GPT-4-turbo, GPT-3.5-turbo

  # Anthropic - Direct Claude access
  - name: anthropic
    api_key: your-anthropic-api-key
    # Automatically configured with Claude models

  # Nvidia - Nemotron models
  - name: nvidia 
    api_key: your-nvidia-api-key

  # Google Gemini
  - name: gemini
    api_key: your-gemini-api-key

# Router configuration for different use cases
router:
  default: openrouter,anthropic/claude-sonnet-4
  think: openai,o1-preview
  long_context: anthropic,claude-sonnet-4
  background: anthropic,claude-3-haiku-20240307
  web_search: openrouter,perplexity/llama-3.1-sonar-huge-128k-online

# config.yaml
domain_mappings:
  localhost: openai # Use OpenAI transformations for localhost requests
  127.0.0.1: gemini # Use Gemini transformations for 127.0.0.1 requests
  custom.api: openrouter # Use OpenRouter transformations for custom APIs

providers:
  name: local-lmstudio
  url: "http://localhost:1234/v1/chat/completions"
  api_key: "not-needed"

# Run Claude Code through the router
cco code [args...]

# Examples:
cco code --help
cco code "Write a Python script to sort a list"
cco code --resume session-name

# Development with hot reload (automatically installs Air if needed)
make dev

# This will:
# - Install Air if not present
# - Start the server with `cco start --verbose`
# - Watch for Go file changes
# - Automatically rebuild and restart on changes

[Unit]
Description=Claude Code Open
After=network.target

[Service]
Type=simple
User=your-user
ExecStart=/usr/local/bin/cco start
# Or if using go install without symlink:
# ExecStart=%h/go/bin/claude-code-open start
# Or with dynamic Go path:
# ExecStartPre=/usr/bin/env bash -c 'echo "GOPATH: $(go env GOPATH)"'
# ExecStart=/usr/bin/env bash -c '"$(go env GOPATH)/bin/claude-code-open" start'
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target

sudo systemctl enable claude-code-open
sudo systemctl start claude-code-open

# Use your OpenAI API key directly with OpenAI
export CCO_API_KEY="sk-your-openai-key"
cco start

# This request will use your OpenAI key:
# - "openai,gpt-4o"

curl http://localhost:6970/health