copilot-api-proxy

A reverse proxy for the GitHub Copilot API that exposes OpenAI and Anthropic compatible endpoints. It forwards requests unchanged and injects the required Copilot authentication headers.

Warning

This is a reverse-engineered proxy of GitHub Copilot API. It is not supported by GitHub, and may break unexpectedly. Use at your own risk.

Warning

GitHub Security Notice: Excessive automated or scripted use of Copilot (including rapid or bulk requests, such as via automated tools) may trigger GitHub's abuse-detection systems. You may receive a warning from GitHub Security, and further anomalous activity could result in temporary suspension of your Copilot access.

GitHub prohibits use of their servers for excessive automated bulk activity or any activity that places undue burden on their infrastructure.

Please review:

• GitHub Acceptable Use Policies
• GitHub Copilot Terms

Use this proxy responsibly to avoid account restrictions.

Features

• OpenAI-compatible endpoints — /v1/chat/completions, /v1/responses, /v1/models
• Anthropic-compatible endpoint — /v1/messages with full request/response conversion
• Pure passthrough — No schema translation for OpenAI endpoints (minimal initiator inference only)
• Streaming support — Server-Sent Events (SSE) for both OpenAI and Anthropic formats
• Tool/function calling — Full support for tool use in both API formats
• Vision support — Image inputs are forwarded with proper Copilot headers
• GitHub OAuth device flow — One-time browser-based authentication
• Automatic token refresh — Copilot tokens are refreshed in the background
• System service — Install as a daemon on macOS/Linux

Requirements

• A GitHub account with an active Copilot subscription

Installation

From source

cargo build --release

The binary will be at target/release/copilot-api-proxy.

Quick Start

1. Authenticate (one-time)

copilot-api-proxy auth

This opens a browser for GitHub OAuth and stores the token at ~/.local/share/copilot-api-proxy/github_token.

2. Start the proxy

# Default port: 9876
copilot-api-proxy server

# Custom port
copilot-api-proxy server --port 8080

# With debug logging
copilot-api-proxy server --log-level debug

3. Use the API

Point your OpenAI or Anthropic client to http://localhost:9876.

API Endpoints

Endpoint	Method	Description
/v1/chat/completions	POST	OpenAI chat completions
/v1/responses	POST	OpenAI responses API (gpt-5 only)
/v1/models	GET	List available models
/v1/messages	POST	Anthropic messages API (converted to OpenAI)
/health	GET	Health check

Usage Examples

OpenAI Chat Completions

curl -X POST http://localhost:9876/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-4o-mini-2024-07-18",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Streaming Response

curl -X POST http://localhost:9876/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-4o-mini-2024-07-18",
    "messages": [{"role": "user", "content": "Hello"}],
    "stream": true
  }'

OpenAI Responses API

curl -X POST http://localhost:9876/v1/responses \
  -H "Content-Type: application/json" \
  -d '{"model": "gpt-5", "input": "Hello"}'

Anthropic Messages API

curl -X POST http://localhost:9876/v1/messages \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-20250514",
    "max_tokens": 1024,
    "messages": [{"role": "user", "content": "Hello"}]
  }'

List Models

curl http://localhost:9876/v1/models

System Service

Install as a system daemon to run automatically on boot:

# Install the service (default port: 9876)
copilot-api-proxy service install

# Install with custom port
copilot-api-proxy service install --port 8080

# Uninstall the service
copilot-api-proxy service uninstall

Configuration

Environment Variables

Variable	Description	Default
GITHUB_TOKEN	Override the stored GitHub token	Token file
ANTHROPIC_API_KEY	Require API key for /v1/messages	None (no auth)
BIG_MODEL	Model for Claude opus requests	claude-opus-4.5
MIDDLE_MODEL	Model for Claude sonnet requests	claude-sonnet-4.5
SMALL_MODEL	Model for Claude haiku requests	claude-haiku-4.5
MAX_TOKENS_LIMIT	Maximum max_tokens for Claude requests	16384
MIN_TOKENS_LIMIT	Minimum max_tokens for Claude requests	100
RUST_LOG	Logging verbosity	info

Logging

# Debug logging for the proxy and HTTP layer
RUST_LOG=copilot_api_proxy=debug,tower_http=debug copilot-api-proxy server

# Trace logging for maximum verbosity
RUST_LOG=trace copilot-api-proxy server

API Key Authentication

To require authentication for the Anthropic-compatible endpoint:

ANTHROPIC_API_KEY=your-secret-key copilot-api-proxy server

Clients must then provide the key via x-api-key header or Authorization: Bearer header.

How It Works

1. Authentication: Uses GitHub's OAuth device flow to obtain a user token
2. Token Exchange: Exchanges the GitHub token for a Copilot API token
3. Auto-refresh: Background task refreshes the Copilot token before expiry
4. Proxying: Forwards requests to api.individual.githubcopilot.com with proper headers
5. Conversion: For /v1/messages, converts between Anthropic and OpenAI formats

X-Initiator Header

The proxy infers whether a request is user-initiated or agent-initiated based on the message history:

• User-initiated: Consumes premium request quota
• Agent-initiated: Uses standard quota

License

MIT