GitHub Copilot CLI Chat

A powerful terminal-based chat application that integrates with GitHub Copilot using real OAuth device flow authentication and dynamic model discovery.

🌟 Features

• 🔐 Real GitHub OAuth Authentication - Secure device flow authentication
• 🤖 Dynamic Model Discovery - Automatically detects available GitHub Copilot models
• 💬 Interactive Terminal Chat - Rich CLI with colored output and commands
• ⚡ Intelligent Caching - Smart model and token caching for performance
• 🔄 Auto Token Refresh - Seamless token management and renewal
• 🎛️ Configurable Settings - Adjust temperature, max tokens, and model selection
• 📝 Session Management - Persistent chat history during sessions
• 🛡️ Robust Error Handling - Graceful fallbacks and detailed error messages

🚀 Quick Start

Prerequisites

• Node.js 18+
• GitHub account with Copilot access
• Terminal with color support

Installation

# Clone the repository
git clone <repository-url>
cd copilot-cli-chat

# Install dependencies
npm install

# Run setup wizard
npm run setup

# Build the project
npm run build

First Run

# Start the application
npm run dev

# Authenticate with GitHub Copilot
/auth

# Start chatting!
Hello, can you help me write a Python function?

🎯 Usage

Authentication Flow

1. Start the app: npm run dev
2. Authenticate: Use /auth command
3. Visit GitHub: Go to the provided URL
4. Enter code: Input the device code shown
5. Start chatting: Begin your conversation!

Available Commands

Command	Description
/help	Show all available commands
/auth	Authenticate with GitHub Copilot
/status	Show authentication and configuration status
/logout	Log out and clear stored credentials
/clear	Clear current chat history
/model [name]	Set or show current model
/models	Show detailed model information with availability
/refresh	Refresh available models from GitHub Copilot API
/temperature [0-2]	Set or show temperature setting
/tokens [1-4000]	Set or show max tokens
/quit, /exit	Exit the application

Example Session

🚀 Welcome to GitHub Copilot CLI Chat!
Type /help for available commands or just start chatting.

> /models
🔍 Fetching detailed model information...

🤖 Available GitHub Copilot Models:
  ✅ gpt-4o (current)
      Owner: github-copilot
  ✅ gpt-4-turbo
      Owner: github-copilot
  ✅ claude-3-5-sonnet-20241022
      Owner: github-copilot

> /model gpt-4o
✅ Model set to: gpt-4o

> Write a Python function to calculate fibonacci numbers
🤖 Thinking...

🤖 GitHub Copilot:
Here's a Python function to calculate Fibonacci numbers:

```python
def fibonacci(n):
    """Calculate the nth Fibonacci number."""
    if n <= 1:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

/temperature 0.3 ✅ Temperature set to: 0.3

## ⚙️ Configuration

### Environment Variables

Create a `.env` file (copy from `.env.example`):

```bash
# Optional: Custom GitHub OAuth App Client ID
GITHUB_COPILOT_CLIENT_ID=your_custom_client_id

# Optional: Enable debug logging
DEBUG_COPILOT_AUTH=true

# Optional: Custom storage location
AUTH_STORAGE_PATH=./copilot-auth.json

Model Configuration

The application automatically discovers available models from your GitHub Copilot subscription:

• Primary: Fetches from official GitHub Copilot models endpoint
• Secondary: Tests known model names (gpt-4o, claude-3-5-sonnet, etc.)
• Fallback: Uses cached models or minimal working set

Default Settings

• Model: First available model (auto-detected)
• Temperature: 0.7
• Max Tokens: 2000
• Cache Timeout: 5 minutes

🏗️ Architecture

Core Components

┌─────────────────┐    ┌──────────────────┐    ┌─────────────────┐
│   CLI Interface │ ── │ GitHub Copilot   │ ── │ Authentication  │
│                 │    │ Provider         │    │ Manager         │
└─────────────────┘    └──────────────────┘    └─────────────────┘
         │                       │                       │
         │                       │                       │
         ▼                       ▼                       ▼
┌─────────────────┐    ┌──────────────────┐    ┌─────────────────┐
│ Chat Session    │    │ Model Discovery  │    │ Token Storage   │
│ Management      │    │ & Caching        │    │ & Refresh       │
└─────────────────┘    └──────────────────┘    └─────────────────┘

Authentication Flow

1. Device Code Request → GitHub OAuth endpoint
2. User Authorization → GitHub web interface
3. Token Exchange → GitHub Copilot API token
4. Secure Storage → Encrypted local storage
5. Auto Refresh → Seamless token renewal

Model Discovery

1. API Endpoint → https://api.githubcopilot.com/models
2. Model Testing → Test known model availability
3. Caching → 5-minute intelligent cache
4. Fallback → Minimal working model set

🛠️ Development

Scripts

npm run dev           # Development mode with auto-reload
npm run build         # Build for production  
npm run start         # Run production build
npm run setup         # Configuration wizard
npm run type-check    # TypeScript type checking
npm run clean         # Clean build artifacts

Project Structure

src/
├── auth/
│   ├── github-copilot.ts    # OAuth authentication logic
│   └── storage.ts           # Persistent token storage
├── providers/
│   └── github-copilot.ts    # Model provider & API integration
├── cli.ts                   # Main CLI application
└── setup.ts                 # Setup wizard

dist/                        # Built files
docs/                        # Documentation

Building from Source

# Clone and setup
git clone <repository-url>
cd copilot-cli-chat
npm install

# Development
npm run dev

# Production build
npm run build
npm start

🔧 Troubleshooting

Authentication Issues

Problem: GitHub Copilot authentication required

• Solution: Run /auth to authenticate
• Check: Ensure you have GitHub Copilot access
• Debug: Set DEBUG_COPILOT_AUTH=true in .env

Problem: Token exchange failed

• Solution: Try /logout then /auth again
• Check: Verify internet connection
• Info: Tokens expire and need refresh

Model Issues

Problem: No models currently available

• Solution: Run /refresh to refresh models
• Check: Verify Copilot subscription is active
• Fallback: App uses default models if discovery fails

Problem: Model not found error

• Solution: Use /models to see available models
• Check: Set model with /model <model-name>
• Info: Models vary by Copilot subscription

API Errors

Problem: 400 - bad request: error: invalid apiVersion

• Status: ✅ Fixed in current version
• Cause: Removed invalid API version headers

Problem: Rate limiting or 429 errors

• Info: GitHub Copilot has usage limits
• Wait: Try again after a short delay
• Check: Monitor usage in GitHub settings

Build Issues

Problem: tsx: not found

• Solution: Run npm install to install dependencies
• Check: Ensure Node.js 18+ is installed

Problem: TypeScript compilation errors

• Solution: Run npm run type-check for details
• Fix: Update code to match TypeScript requirements

📊 Monitoring & Debugging

Debug Mode

Enable detailed logging:

# In .env file
DEBUG_COPILOT_AUTH=true

# Run with debug output
npm run dev

Storage Location

Authentication data is stored securely at:

• Default: ~/.copilot-cli/auth.json
• Custom: Set AUTH_STORAGE_PATH environment variable
• Permissions: 600 (owner read/write only)

Log Output

[Copilot Auth] Starting device flow authorization
[Copilot Auth] Device flow initiated successfully
✅ Model gpt-4o is available
❌ Model claude-3-5-sonnet-20241022 is not available

🤝 Contributing

We welcome contributions! Please see our Contributing Guide for details.

Development Setup

1. Fork the repository
2. Create a feature branch: git checkout -b feature/amazing-feature
3. Make your changes
4. Add tests if applicable
5. Ensure builds pass: npm run build
6. Commit changes: git commit -m 'Add amazing feature'
7. Push to branch: git push origin feature/amazing-feature
8. Submit a Pull Request

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• GitHub Copilot - For the amazing AI assistance
• OpenCode - For authentication patterns and architecture inspiration
• VS Code Team - For OAuth client ID reference implementation
• Node.js Community - For excellent tooling and libraries

📞 Support

• 🐛 Bug Reports: GitHub Issues
• 💡 Feature Requests: GitHub Discussions
• 📖 Documentation: Check the /docs folder
• ❓ Questions: Use /help command in the CLI

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