GitHub Copilot

Access GitHub Copilot Chat models via the Copilot API with automatic OAuth device-flow authentication and token management.

Prerequisites

• A GitHub account with an active Copilot Individual, Copilot Business, or Copilot Enterprise subscription
• Optionally, a GitHub personal access token (otherwise, interactive device-flow login is used)

Quick Setup

1. Authenticate

On first use, PRX will prompt you to authenticate via GitHub's device code flow:

GitHub Copilot authentication is required.
Visit: https://github.com/login/device
Code: XXXX-XXXX
Waiting for authorization...

Alternatively, provide a GitHub token directly:

export GITHUB_TOKEN="ghp_..."

2. Configure

[default]
provider = "copilot"
model = "gpt-4o"

3. Verify

prx doctor models

Available Models

GitHub Copilot provides access to a curated set of models. The exact models available depend on your Copilot subscription tier:

Model	Context	Vision	Tool Use	Notes
gpt-4o	128K	Yes	Yes	Default Copilot model
gpt-4o-mini	128K	Yes	Yes	Faster, cost-effective
claude-sonnet-4	200K	Yes	Yes	Available on Copilot Enterprise
o3-mini	128K	No	Yes	Reasoning model

Model availability may vary based on your GitHub Copilot plan and GitHub's current model offerings.

Configuration Reference

Field	Type	Default	Description
api_key	string	optional	GitHub personal access token (ghp_... or gho_...)
model	string	gpt-4o	Default model to use

Features

Zero-Config Authentication

The Copilot provider implements the same OAuth device-code flow used by VS Code's Copilot extension:

1. Device code request: PRX requests a device code from GitHub
2. User authorization: You visit github.com/login/device and enter the code
3. Token exchange: The GitHub OAuth token is exchanged for a short-lived Copilot API key
4. Automatic caching: Tokens are cached to ~/.config/openprx/copilot/ with secure file permissions (0600)
5. Auto-refresh: Expired Copilot API keys are automatically re-exchanged without re-authentication

Secure Token Storage

Tokens are stored with strict security:

• Directory: ~/.config/openprx/copilot/ with 0700 permissions
• Files: access-token and api-key.json with 0600 permissions
• On non-Unix platforms, standard file creation is used

Dynamic API Endpoint

The Copilot API key response includes an endpoints.api field that specifies the actual API endpoint. PRX respects this, falling back to https://api.githubcopilot.com when no endpoint is specified.

Native Tool Calling

Tools are sent in OpenAI-compatible format via the Copilot Chat Completions API (/chat/completions). The provider supports tool_choice: "auto" for automatic tool selection.

Editor Headers

Requests include standard Copilot editor identification headers:

• Editor-Version: vscode/1.85.1
• Editor-Plugin-Version: copilot/1.155.0
• User-Agent: GithubCopilot/1.155.0

Troubleshooting

"Failed to get Copilot API key (401/403)"

Your GitHub OAuth token may be expired or your Copilot subscription is inactive:

• Ensure your GitHub account has an active Copilot subscription
• PRX automatically clears the cached access token on 401/403 and will re-prompt for device-flow login

"Timed out waiting for GitHub authorization"

The device code flow has a 15-minute timeout. If it expires:

• Run your PRX command again to get a new code
• Make sure you visit the correct URL and enter the exact code shown

"GitHub device authorization expired"

The device code has expired. Simply retry your command to start a new authorization flow.

Models not available

The available models depend on your Copilot subscription tier:

• Copilot Individual: GPT-4o, GPT-4o-mini
• Copilot Business/Enterprise: May include additional models like Claude

Check your subscription at github.com/settings/copilot.

Rate limiting

GitHub Copilot has its own rate limits separate from OpenAI. If you encounter rate limiting, consider using fallback_providers in your PRX configuration to fall back to another provider.