Lesson 7: GitHub Copilot CLI

Session Duration: 45 minutes
Audience: Embedded/C++ Developers (Intermediate to Advanced)
Environment: Windows + PowerShell 7+ (also Linux, macOS, WSL)
Focus: Terminal-based AI agent for embedded development workflows

Overview

GitHub Copilot CLI is an AI agent that operates directly from your terminal. It can answer questions, write and debug code, interact with GitHub.com, and execute shell commands—all through natural language prompts.

What You’ll Learn:

• Install and authenticate Copilot CLI
• Use interactive and programmatic modes
• Leverage file references, shell integration, and GitHub.com tasks
• Customize with MCP servers, custom agents, and instructions

Key Concepts:

Agenda (45 min)

Table of Contents

• Overview
• Agenda (45 min)
• Prerequisites
• 1. Installation
• 2. Authentication
• 3. Modes of Use
• 4. Model Selection
• 5. Key Features Demo
• 6. Customization
• 7. Hands-On Exercises
• Quick Reference
• Troubleshooting
• GitHub Copilot SDK
• Additional Resources

Prerequisites

Before starting this session, ensure you have:

• ✅ Windows 10/11 with PowerShell 7+ (or Linux/macOS/WSL)
• ✅ GitHub account with Copilot Pro, Pro+, Business, or Enterprise
• ✅ Git installed and configured
• ✅ Workshop repository cloned locally

Verify Your Environment

# Check PowerShell version (need 7+)
$PSVersionTable.PSVersion

# Check Git is available
git --version

1. Installation

Windows (winget)

winget install GitHub.Copilot

Restart PowerShell after installation

macOS (Homebrew)

brew install github/copilot-cli/copilot

Verify Installation

copilot --version

Fallback: Direct Download

If package manager fails, download from GitHub Releases

2. Authentication

Launch & Login

cd C:\path\to\workshop-repo
copilot

/login

Authentication Flow

1. Copy the device code displayed
2. Open https://github.com/login/device
3. Enter code and authorize
4. Return to terminal — “Successfully authenticated!”

Trust Directory

When prompted, choose “Yes, always trust this folder” for your projects.

Warning: Only launch Copilot CLI from directories you trust. Do not launch from your home directory or directories with sensitive data.

3. Modes of Use

Interactive Mode (Default)

Start a multi-turn conversation session:

copilot

Programmatic Mode

Run a single prompt and exit—ideal for scripts and automation:

copilot -p "Show me this week's commits and summarize them" --allow-tool 'shell(git)'

Tool Approval Options

Example: Allow git but block destructive commands:

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

4. Model Selection

The default model is Claude Sonnet 4.5. Change models with:

/model

Select from available models—each shows a multiplier for premium request usage (e.g., Claude Sonnet 4.5 (1x)).

5. Key Features Demo

Local Tasks

Code Analysis:

Explain @Firmware/MotorControl/motor.cpp
What functions are in @Firmware/Drivers/spi_driver.c?

Code Generation:

Add a factorial function to @src\utils.c
Suggest improvements to @Firmware/MotorControl/encoder.cpp

Git Operations:

Commit the changes to this repo
Show me the last 5 changes made to CHANGELOG.md
Revert the last commit, leaving changes unstaged

GitHub.com Integration

Pull Requests:

List my open PRs
Create a PR that updates the README at https://github.com/owner/repo
Check the changes in PR https://github.com/owner/repo/pull/123
Merge all open PRs that I created in owner/repo

Issues:

List all open issues assigned to me in owner/repo
Raise an improvement issue in owner/repo for the unclosed file handle
I've been assigned this issue: https://github.com/owner/repo/issues/123. Start working on it.

GitHub Actions:

List any Actions workflows in this repo that add comments to PRs
Create a workflow that runs eslint on PRs and fails if errors are found

Shell Integration

!git status
!git log --oneline -5
How many lines of code are in src\?

6. Customization

Slash Commands

7. Hands-On Exercises

Exercise 1: Get Oriented (3 min)

cd C:\path\to\workshop-repo
copilot

/help
/model
What is this project and what does it do?

Exercise 2: Local Tasks (5 min)

Explain @Firmware/MotorControl/motor.cpp
What functions are defined in @Firmware/Drivers/spi_driver.c?
Suggest improvements to @Firmware/Board/v3/board.cpp

Exercise 3: GitHub.com Tasks (5 min)

List my open PRs
List all open issues assigned to me in <your-repo>
Check the changes in PR https://github.com/<owner>/<repo>/pull/<number>

Exercise 4: Code Generation (4 min)

Add a function to @src\utils.c that calculates factorial
Create @src\logger.c with debug, info, error logging functions

Review and approve/reject proposed changes

Exercise 4: Code Generation (4 min)

Add a function to @src\utils.c that calculates factorial
Create @src\logger.c with debug, info, error logging functions

Review and approve/reject proposed changes

Exercise 5: Git Integration (3 min)

!git log --oneline -5
Show me what files changed in the last commit
Commit the staged changes with a descriptive message

Quick Reference

Essential Commands

Common Prompts

Troubleshooting

GitHub Copilot SDK

While Copilot CLI is an interactive terminal tool for developers, the GitHub Copilot SDK is a programmatic library that lets you embed Copilot’s agentic capabilities directly into your own applications and services.

CLI vs SDK: When to Use Each

SDK Installation

Prerequisite: The Copilot CLI must be installed. The SDK communicates with the CLI running in server mode via JSON-RPC.

Quick Demo: Python

from github_copilot_sdk import CopilotClient

# SDK automatically starts CLI in server mode
client = CopilotClient()

# Analyze firmware code programmatically
response = client.chat(
    "Review @Firmware/MotorControl/motor.cpp for potential issues"
)
print(response)

Use Case: Automated Firmware Documentation

Build a script that generates documentation for your embedded codebase:

from github_copilot_sdk import CopilotClient
import os

client = CopilotClient()

# Generate docs for each driver file
for file in os.listdir("Firmware/Drivers"):
    if file.endswith(".c"):
        doc = client.chat(f"Generate API documentation for @Firmware/Drivers/{file}")
        with open(f"docs/{file}.md", "w") as f:
            f.write(doc)

This enables CI/CD integration, batch processing, and custom tooling that would be impractical with interactive CLI sessions.

SDK Resources

• GitHub Copilot SDK Repository
• Getting Started Guide
• Cookbook & Recipes

Note: The SDK is currently in Technical Preview.

Additional Resources

Microsoft Learn Documentation

Official Documentation

• About GitHub Copilot CLI - Comprehensive feature overview
• Installing GitHub Copilot CLI - Installation guide
• Using GitHub Copilot CLI - Usage patterns
• Copilot Subscription - Manage your subscription