Claude Code via GitHub Copilot

Use Claude Code for free by routing it through your existing GitHub Copilot subscription.

This project runs a lightweight local proxy that translates between Anthropic's Messages API (which Claude Code speaks) and OpenAI's Chat Completions API (which GitHub Copilot speaks). No Anthropic API key needed — just your Copilot subscription.

Features

• Full API Translation — Anthropic Messages API ↔ OpenAI Chat Completions, including streaming
• Web Search — Emulates Anthropic's web_search_20250305 tool using DuckDuckGo Lite (free) or Brave Search API
• Docker Support — Run the proxy as an always-on container that survives reboots
• Zero Dependencies — Pure Node.js, no npm install needed

Prerequisites

• GitHub account with an active Copilot subscription (Individual, Business, or Enterprise)
• Node.js 18+ (or Docker)
• Claude Code installed (npm install -g @anthropic-ai/claude-code)

Quick Start

1. Clone and authenticate

git clone https://github.com/samarth777/claude-code-copilot.git
cd claude-code-copilot
node scripts/auth.mjs

The auth script opens a GitHub device code flow in your browser. Your token is saved to ~/.claude-copilot-auth.json.

2. Start Claude Code

One-command launcher (recommended):

./scripts/launch.sh

This auto-starts the proxy (via Docker if available, otherwise as a background process) and launches Claude Code.

Or use Docker directly:

docker compose up -d
ANTHROPIC_BASE_URL=http://localhost:18080 ANTHROPIC_API_KEY=copilot-proxy claude

The proxy runs with restart: always — it stays running across reboots.

3. Select your model

Inside Claude Code, use /model to switch between available models (Claude Opus, Sonnet, etc.).

Web Search

The proxy emulates Anthropic's web search tool so Claude Code's WebSearch works automatically.

Search providers:

• Brave Search API — Best results. Set BRAVE_API_KEY env var (free tier: 2000 queries/month at api.search.brave.com)
• DuckDuckGo Lite — Free, no API key needed (default)

How It Works

Claude Code sends requests in Anthropic format → proxy translates to OpenAI format → forwarded to GitHub Copilot → responses translated back. No data is stored or logged.

Troubleshooting

"401 Unauthorized" from Copilot

rm ~/.claude-copilot-auth.json
node scripts/auth.mjs

"EADDRINUSE: address already in use"

lsof -ti:18080 | xargs kill -9

Proxy running but Claude Code shows errors

Make sure both environment variables are set:

ANTHROPIC_BASE_URL=http://localhost:18080 ANTHROPIC_API_KEY=copilot-proxy claude

Configuration

Variable	Default	Description
COPILOT_PROXY_PORT	18080	Port for the local proxy
COPILOT_AUTH_FILE	~/.claude-copilot-auth.json	Path to saved OAuth token
BRAVE_API_KEY	(none)	Brave Search API key for web search
WEB_SEARCH_MAX_RESULTS	5	Max search results per query

License

MIT