github-copilot-cli-expert

GitHub Copilot CLI Expert

Comprehensive knowledge of GitHub Copilot CLI - the terminal-native AI coding assistant.

Note: Command syntax and model availability may change. Run /help in Copilot CLI for current options.

Purpose

This skill provides expert guidance on:

1. Installing and updating GitHub Copilot CLI
2. All slash commands and keyboard shortcuts
3. Custom agents, skills, and MCP server configuration
4. Security, permissions, and trusted directories
5. Integration with GitHub workflows (PRs, issues, Actions)
6. Programmatic and interactive usage modes

Quick Reference

Installation (Pick One)

# Homebrew (macOS/Linux) - Recommended
brew install copilot-cli

# npm (all platforms, requires Node.js 22+)
npm install -g @github/copilot

# WinGet (Windows)
winget install GitHub.Copilot

# Install script (macOS/Linux)
curl -fsSL https://gh.io/copilot-install | bash

Update to Latest Version

# Homebrew
brew upgrade copilot-cli

# npm
npm update -g @github/copilot

# WinGet
winget upgrade GitHub.Copilot

# Check version
copilot --version

Before First Use

Requirements:

• Active GitHub Copilot subscription (Plans)
• Node.js 22+ (if installing via npm)
• PowerShell v6+ (Windows users)

Authentication:

# On first run, you'll be prompted to login
copilot
# Then: /login

# OR set environment variable
export GH_TOKEN="ghp_xxxxxxxxxxxx"

Essential Slash Commands

Command	Description
/help	Show all commands and shortcuts
/model	Select AI model (claude-sonnet-4-5, gpt-5, etc.)
/mcp	Manage MCP server configuration
/agent	Browse and select custom agents
/delegate	Hand off task to Copilot coding agent on GitHub
/compact	Reduce context window usage
/context	Show token usage visualization
/usage	Display session metrics
/diff	Review changes made in session
/share	Export session to file or gist
/skills	Manage skills for enhanced capabilities

Keyboard Shortcuts

Shortcut	Action
@file	Include file contents in context
!cmd	Execute shell command directly
Esc	Cancel operation / exit prompt
Ctrl+C	Cancel / clear / exit
Ctrl+L	Clear screen
Ctrl+O	Expand/collapse timeline
↑/↓	Navigate command history

When to Use This Skill

Auto-triggers when user mentions:

• "copilot cli", "github copilot", "install copilot"
• "update copilot", "copilot version", "copilot commands"
• "mcp server", "custom agents", "copilot skills"

Explicitly invoke via:

Skill(skill="github-copilot-cli-expert")

Navigation Guide

When to Read Supporting Files

reference.md - Read when you need:

• Complete list of all slash commands with detailed options
• All command-line flags and environment variables
• Detailed security configuration (trusted directories, tool permissions)
• Programmatic mode examples and scripting patterns
• MCP server configuration JSON format

examples.md - Read when you need:

• Step-by-step workflow examples (PR creation, code review)
• Custom agent creation and invocation examples
• GitHub integration use cases (issues, Actions, PRs)
• Delegation to Copilot coding agent workflows

Core Capabilities

1. Interactive vs Programmatic Mode

Interactive (default):

copilot
# Then type prompts naturally

Programmatic (scripting):

copilot -p "Summarize recent commits" --allow-tool 'shell(git)'

2. Custom Agents

Built-in agents: explore, task, plan, code-review

Custom agent locations:

• User-level: ~/.copilot/agents/
• Repository: .github/agents/
• Org/Enterprise: .github-private/agents/

3. MCP Servers

GitHub MCP server included by default. Add more:

/mcp add
# Fill details, Ctrl+S to save

Config stored in: ~/.copilot/mcp-config.json

4. Security Model

• Trusted directories: Confirmed on first launch
• Tool approval: Required for file modifications
• Path permissions: Current directory + temp by default
• URL permissions: All URLs require approval

Common Patterns

Include Files in Prompts

Explain @config/settings.yml
Fix the bug in @src/app.js

Delegate to GitHub Agent

/delegate complete the API tests and create a PR

Resume Previous Session

copilot --resume    # Cycle through sessions
copilot --continue  # Resume most recent

Allow Tools Without Prompts

copilot --allow-all-tools
copilot --allow-tool 'shell(git)'
copilot --deny-tool 'shell(rm)'

Version Information

Current Version: Check with copilot --version

Prerelease Channels:

brew install copilot-cli@prerelease
npm install -g @github/copilot@prerelease
winget install GitHub.Copilot.Prerelease

Releases: https://github.com/github/copilot-cli/releases/

Troubleshooting

Authentication Issues

/login              # In interactive mode
# Or use PAT with GH_TOKEN/GITHUB_TOKEN env var

Context Window Full

/compact            # Summarize conversation
/context            # View token usage

MCP Server Not Loading

/mcp show           # List configured servers
/mcp edit [name]    # Edit configuration

Tool Permission Denied

• Check trusted directories: ~/.copilot/config.json → trusted_folders
• Use --allow-all-paths or --allow-all-urls flags
• Approve tools individually when prompted

First-Time Setup Issues

"Copilot not found" after install:

• Restart terminal after installation
• Check PATH includes install location
• Run which copilot (Unix) or where copilot (Windows)

"No subscription" error:

• Verify at https://github.com/settings/copilot
• Ensure plan includes CLI access
• Try /logout then /login

Related Skills

• mcp-manager: Advanced MCP server configuration
• agent-sdk: Building custom agents
• documentation-writing: Clear documentation practices

Official Resources

• Docs: https://docs.github.com/copilot/concepts/agents/about-copilot-cli
• Usage Guide: https://docs.github.com/copilot/how-tos/use-copilot-agents/use-copilot-cli
• Installation: https://docs.github.com/copilot/how-tos/set-up/install-copilot-cli
• Releases: https://github.com/github/copilot-cli/releases/
• Feedback: Use /feedback command in CLI