Dockerized copilot-api-js reverse proxy that exposes GitHub Copilot's API as OpenAI/Anthropic compatible endpoints. Secured with Caddy reverse proxy (Bearer token auth + UI basic auth), with optional Dev Tunnel or Tailscale networking for remote device access.

# Full setup (generates tokens, OAuth login, configures Claude Code) (token + ui-password + login + setup-claude)
./copilotproxy.ps1 init

# Start the proxy (local only)
./copilotproxy.ps1 start

The proxy will be available at http://localhost:4141. UI is available at http://localhost:4141/ui.

Dev Tunnel runs locally on your host machine and tunnels port 4141 to another device.

On host:

./copilotproxy.ps1 devtunnel-auth        # One-time: login + create tunnel (saved to .env)
./copilotproxy.ps1 start                 # Start the proxy
./copilotproxy.ps1 devtunnel-start       # Host the tunnel in background
./copilotproxy.ps1 setup-claude-remote   # Start setup approval server

On remote device:

1. Open the tunnel URL in your browser (printed by devtunnel-start, e.g. https://<id>-4141.<region>.devtunnels.ms/setup)
2. Sign in with the same Microsoft/GitHub account that owns the tunnel
3. Click Download and approve on the host machine when prompted
4. Review, then run the script:

cat ~/Downloads/claude-copilot-proxy.sh   # Review first
sh ~/Downloads/claude-copilot-proxy.sh    # Installs devtunnel, connects, configures Claude

The setup script handles everything: installs devtunnel CLI if needed, logs in, starts devtunnel connect in the background with auto-reconnect, and configures Claude Code.

Manage the connection on the remote device:

sh claude-copilot-proxy.sh reconnect   # Restart devtunnel connect
sh claude-copilot-proxy.sh stop        # Stop devtunnel connect
sh claude-copilot-proxy.sh disable     # Remove proxy config from Claude

Tailscale runs as a sidecar container — the proxy container stays unprivileged.

On host:

./copilotproxy.ps1 tailscale-auth        # One-time Tailscale login
./copilotproxy.ps1 tailscale-start       # Start with Tailscale sidecar
./copilotproxy.ps1 setup-claude-remote   # Start setup approval server

On remote device (must have Tailscale installed and joined to the same tailnet):

1. Navigate to http://copilot-proxy:4141/setup for step-by-step instructions
2. Click Download and approve on the host machine when prompted
3. Review, then run the script:

cat ~/Downloads/claude-copilot-proxy.sh   # Review first
sh ~/Downloads/claude-copilot-proxy.sh    # Configures Claude Code

Approve on the host machine when prompted.

Dev Tunnel runs locally on the host (not in Docker). Requires the devtunnel CLI (winget install Microsoft.devtunnel).

Tailscale runs as a separate sidecar container — the proxy container stays unprivileged.

copilot-api-js has no built-in authentication or access control — anyone who can reach it gets full access to your Copilot API. Caddy sits in front as a security layer to lock it down:

• Bearer token auth on all API endpoints (v1/models, chat/completions, etc.)
• Basic auth on UI, models, and history pages
• CORS headers stripped — copilot-api-js adds Access-Control-Allow-Origin: * by default; Caddy strips these headers to enforce same-origin policy, preventing any external website from making requests to your proxy
• copilot-proxy binds to localhost — only Caddy can reach it, not the network directly
• Health endpoint (/health) is unauthenticated for monitoring
• /setup serves a static instructions page (no credentials); /setup.sh only works when the approval server is running and requires interactive approval

Both remote access options add a network-level authentication layer on top of Caddy's auth:

• Dev Tunnel — Tunnels are private by default: only the Microsoft/GitHub account that created the tunnel can devtunnel connect to it. Remote devices must authenticate with devtunnel login using the same account. Widening access (org/public) is not allowed or endorsed by this project — the proxy is intended for single-user access only. See Dev Tunnel access control for details.
• Tailscale — Only devices joined to your tailnet can reach the proxy. Tailscale uses WireGuard for encrypted point-to-point connections. No ports are exposed to the public internet. Sharing the proxy with others via Tailscale sharing or ACLs is not allowed or endorsed by this project.

┌─────────────────────────────────────────────────┐
│              shared network namespace            │
│                                                  │
│  ┌───────────────────────────────────────────┐   │
│  │ Caddy (reverse proxy)                     │   │
│  │ :4141 — Bearer auth, basic auth, CORS     │   │
│  │   /setup    → static HTML instructions    │   │
│  │   /setup.sh → setup-server (approval)     │   │
│  │   /*        → copilot-api-js              │   │
│  └───────────────────────────────────────────┘   │
│                                                  │
│  ┌───────────────────────────────────────────┐   │
│  │ copilot-api-js (bun)                      │   │
│  │ :4142 (localhost only, via Caddy)          │   │
│  └───────────────────────────────────────────┘   │
│                                                  │
│  ┌───────────────────────────────────────────┐   │
│  │ setup-server (ephemeral, on-demand)       │   │
│  │ :4143 — interactive device approval       │   │
│  │ serves remote-setup.sh after approval     │   │
│  └───────────────────────────────────────────┘   │
│                                                  │
│  ┌───────────────────────────────────────────┐   │  (optional)
│  │ tailscale sidecar (NET_ADMIN)             │   │
│  │ publishes :4141 to tailnet                │   │
│  └───────────────────────────────────────────┘   │
│                                                  │
│         devtunnel (runs on host, not Docker)     │  (optional)
│         tunnels :4141 to remote devices          │
└─────────────────────────────────────────────────┘

• Caddyfile — Reverse proxy config: Bearer auth, basic auth, CORS stripping, /setup routing
• setup.html — Static setup instructions page served by Caddy at /setup
• Dockerfile — Multi-stage build: clones and builds copilot-api-js at pinned commit
• Dockerfile.tailscale — Lightweight sidecar based on tailscale/tailscale:v1.96.5
• docker-compose.yaml — Local-only, no elevated privileges
• docker-compose.tailscale.yaml — Overlay that adds sidecar + network_mode: service:tailscale

Edit config.yaml to customize model overrides, rate limiting, timeouts, and more. See the upstream config.example.yaml for all options.

The default config upgrades model aliases:

model_overrides:
  opus: claude-opus-4.6-1m
  haiku: claude-sonnet-4.6
  claude-haiku-4.5: claude-sonnet-4.6

Running in a container isolates npm/bun dependencies from your host machine, mitigating supply chain risks. The proxy handles your GitHub token — keeping that in an isolated container with no host filesystem access is a good security practice.

Images are published to GHCR on every push to main:

ghcr.io/nathan815/copilot-proxy:latest
ghcr.io/nathan815/copilot-proxy-tailscale:latest