G

GitHub

Where code lives and changes are reviewed. Also the place most AI coding agents deliver their work, as pull requests.

6 chapters9 tutorialsOfficial site

01 · Introduction

What GitHub is

Git keeps a history of every change to a set of files. GitHub is a website that hosts those histories and adds the teamwork around them.

The words you will meet:

  • Repository (repo): one project and its full history.
  • Commit: one saved change with a message saying why.
  • Branch: a side copy where you work without touching the main version.
  • Pull request (PR): "here is my branch, please review and merge it". This is where discussion and review happen.
  • Issue: a ticket for a bug or a task.
  • Actions: automation that runs when something changes, for example tests on every pull request.

AI coding agents (Codex, Claude Code, Copilot) read a repository and deliver their work as a pull request, so a little GitHub fluency goes a long way.

02 · When to use it

When you need it

  • You work with an AI coding agent and want to see, review and undo its changes.
  • A small team shares scripts, prompts or configuration and needs one place with history.
  • You want tests or deployments to run automatically when something changes.
  • You publish something others may reuse: a tool, a template, a dataset.

03 · Setup

Getting started

  1. Create an account at github.com and turn on two-factor authentication.
  2. Install GitHub Desktop (no command line needed) or the git command.
  3. Create a repository, clone it to your computer, add a file, commit with a message, push.
  4. Make a branch, change something, open a pull request on the website, merge it.

Do this once with a throwaway project; after that the agents' pull requests will make sense.

04 · How to use it

Day-to-day use

  • Read a pull request file by file, not as one wall of green and red. Leave comments on the lines you question.
  • Let Actions run the tests on every pull request; a red check is a free reviewer.
  • Write commit messages that say why, not what; the diff already shows what.
  • Keep secrets out of the repository. Use the repository's Secrets settings for Actions and an .env file ignored by git locally.
  • Copilot (GitHub's own assistant) can review pull requests and suggest fixes inside the website.

05 · Pitfalls

Pitfalls

  • A committed API key is public the moment the repository is, and stays in history after you delete it. Rotate it.
  • Merging a pull request you did not read is the same as writing the code yourself.
  • Force-pushing rewrites history and can erase a colleague's work; avoid it on shared branches.
  • Free private repositories have limits on Actions minutes; large test suites can hit them.

06 · Resources

Where to go next

The Skills course and the Copilot pages cover everything a non-developer needs.

My notes

Sign in to keep private notes on this handbook.Sign in