copilot-proxy-go

README

Copilot Proxy Go

Use GitHub Copilot with Claude Code, Codex CLI, Cursor, OpenCode, and any OpenAI/Anthropic-compatible client.

copilot-proxy-go is a local Go proxy that turns your GitHub Copilot subscription into OpenAI-compatible and Anthropic-compatible API endpoints, with first-class setup for Claude Code and Codex CLI.

Works Great With

Tool	One-command setup	API
Claude Code	./copilot-proxy-go start --claude-code	Anthropic Messages API
Codex CLI	./copilot-proxy-go start --codex	OpenAI Responses API

Highlights

• Claude Code ready — interactive model selection and environment generation with --claude-code
• Codex CLI ready — generates a Responses API configuration with --codex
• VPN/proxy friendly — use --proxy-env to route GitHub/Copilot requests through http_proxy, https_proxy, or all_proxy
• OpenAI + Anthropic compatible — supports Chat Completions, Responses, Messages, and Embeddings
• Copilot-backed — uses your GitHub Copilot account as the backend model provider
• Token management — GitHub OAuth device-code flow with automatic Copilot token refresh

Quick Start

1. Build

go build -o copilot-proxy-go .

2. Authenticate

./copilot-proxy-go auth

This opens a GitHub device-code flow in your browser. The token is saved to ~/.local/share/copilot-proxy-go/github_token.

3. Start for your client

Claude Code:

./copilot-proxy-go start --claude-code

Codex CLI:

./copilot-proxy-go start --codex

Generic OpenAI/Anthropic-compatible server:

./copilot-proxy-go start

The proxy runs on http://localhost:4141. OpenAI-compatible clients should use http://localhost:4141/v1 as the base URL.

Behind a VPN or proxy

If GitHub or Copilot requires a proxy in your network, export your proxy variables and start with --proxy-env:

export https_proxy=http://127.0.0.1:7890 \
  http_proxy=http://127.0.0.1:7890 \
  all_proxy=socks5://127.0.0.1:7890

./copilot-proxy-go start --proxy-env

Features

• Multi-API support — Chat Completions, Messages (Anthropic), Responses, Embeddings
• Automatic translation — routes Anthropic requests to the best available backend (native Messages API → Responses API → Chat Completions)
• Extended thinking — full support for Claude thinking/reasoning blocks with interleaved thinking protocol
• Streaming — SSE streaming with proper event translation across all API formats
• Quota optimization — auto-routes compact/warmup requests to smaller models to save premium quota
• Local dashboard — view usage, request metrics, session state, and quota information in your browser

Dashboard

Usage with Claude Code

./copilot-proxy-go start --claude-code

This interactively selects models and generates the environment variables for Claude Code. Or set them manually:

export ANTHROPIC_BASE_URL=http://localhost:4141
export ANTHROPIC_AUTH_TOKEN=copilot-proxy
export ANTHROPIC_MODEL=claude-sonnet-4
export ANTHROPIC_SMALL_FAST_MODEL=gpt-5-mini
claude

Usage with Codex CLI

./copilot-proxy-go start --codex

This interactively selects a Responses-capable model and generates a Codex command. Or set it manually:

export CODEX_API_KEY=copilot-proxy
export NO_PROXY=localhost,127.0.0.1,::1
export no_proxy=localhost,127.0.0.1,::1
codex \
  -c 'model="gpt-5.3-codex"' \
  -c 'model_provider="copilot-proxy"' \
  -c 'model_providers.copilot-proxy.name="Copilot Proxy"' \
  -c 'model_providers.copilot-proxy.base_url="http://127.0.0.1:4141/v1"' \
  -c 'model_providers.copilot-proxy.env_key="CODEX_API_KEY"' \
  -c 'model_providers.copilot-proxy.wire_api="responses"'

API Endpoints

Endpoint	Method	Description
/v1/messages	POST	Anthropic Messages API
/v1/messages/count_tokens	POST	Token counting
/chat/completions	POST	OpenAI Chat Completions
/v1/chat/completions	POST	OpenAI Chat Completions
/responses	POST	OpenAI Responses API
/v1/responses	POST	OpenAI Responses API
/embeddings	POST	Embeddings
/models	GET	List available models
/v1/models	GET	List available models
/dashboard	GET	Usage dashboard (web UI)

CLI Reference

start — Run the proxy server

copilot-proxy-go start [flags]

Flags:
  -p, --port int              port to listen on (default 4141)
  -g, --github-token string   GitHub OAuth token (skips device code flow)
  -a, --account-type string   individual, business, or enterprise (default "individual")
  -c, --claude-code           interactive model selection for Claude Code
      --codex                 interactive model selection for Codex CLI
  -v, --verbose               enable verbose/debug logging
  -r, --rate-limit int        minimum seconds between requests (0 = disabled)
  -w, --wait                  wait instead of rejecting on rate limit
      --manual                require manual CLI approval for each request
      --proxy-env             enable HTTP proxy from env vars (http_proxy/https_proxy/all_proxy)
      --show-token            print tokens to console

auth — Authenticate with GitHub

copilot-proxy-go auth [flags]

Flags:
      --force        force re-authentication
      --show-token   print token to console

License

MIT