GitHub Mastery Guide

A complete technical reference — from Git internals to enterprise DevOps

Five modules · Internals to platform engineering · Diagrams · Real-world patterns

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Table of Contents

#	Module	Core Topics	Depth
01	Fundamentals	Git object model · refs · branching · merging · rebasing	●●●○○
02	Collaboration	Issues · Pull Requests · Code Review · Projects · CODEOWNERS	●●●○○
03	GitHub Actions	Workflows · triggers · matrix · secrets · reusable workflows · custom actions	●●●●○
04	Advanced Platform	CLI · REST API · GraphQL · webhooks · security · packages	●●●●●
05	Git Workflows	GitHub Flow · GitFlow · trunk-based · release strategies	●●●●○

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Who This Guide Is For

Target audience: Engineers who know the basics and want to work at the edge of the platform.

You should already know:

• git add, git commit, git push
• What a branch is
• What a pull request is

This guide builds from there — covering the why behind Git's design, the full surface of GitHub's collaboration and automation platform, and the patterns used by high-performing engineering teams.

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Quick-Start Reference

Repository Bootstrap

# Standard clone
git clone https://github.com/owner/repo.git

# Shallow clone — fastest for large repos (CI, build agents)
git clone --depth 1 https://github.com/owner/repo.git

# Restore full history later
git fetch --unshallow

# Clone a specific branch
git clone --branch release/2.0 --single-branch https://github.com/owner/repo.git

Daily Driver Commands

Action	Command	Key Detail
Create + switch branch	git switch -c feat/name	Modern checkout -b
Stage in hunks	git add -p	Interactive — never over-commit
Commit with message	git commit -m "feat(auth): add OAuth2 flow"	Conventional Commits format
Amend last commit	git commit --amend --no-edit	Unpushed commits only
Soft undo last commit	git reset HEAD~1	Keeps working tree changes
Named stash	git stash push -m "wip: auth refactor"	Findable later
List stashes	git stash list	stash@{0} is newest
Commits ahead of main	git log main..HEAD --oneline	Before opening a PR
Interactive rebase	git rebase -i HEAD~5	Squash, reword, drop
Show file at commit	git show abc1234:src/app.ts	Without checkout

GitHub CLI One-Liners

# Pull Requests
gh pr create --fill --assignee @me --draft
gh pr view --web                          # Open in browser
gh pr merge --squash --delete-branch

# Issues
gh issue create --title "Bug: login fails" --label bug
gh issue list --label "priority:high" --state open --json number,title

# Actions
gh run list --workflow=ci.yml
gh run watch                              # Tail live output
gh run rerun --failed                     # Retry only failed jobs

# Repos
gh repo create myorg/myrepo --private --clone
gh repo fork owner/repo --clone --remote

# API (raw access)
gh api repos/{owner}/{repo}/actions/runs --jq '.workflow_runs[0].status'

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How to Navigate This Guide

README  ←  You are here
  │
  ├── 01-fundamentals.md ──── "How does Git actually work?"
  │     └── Object model, SHA hashing, refs, merge strategies
  │
  ├── 02-collaboration.md ─── "How do teams work effectively?"
  │     └── Issues, PRs, review, projects, branch protection
  │
  ├── 03-actions.md ──────── "How do I automate everything?"
  │     └── CI/CD, matrix builds, custom actions, secrets
  │
  ├── 04-advanced.md ─────── "How do I build on the platform?"
  │     └── API, CLI, webhooks, security, packages, pages
  │
  └── 05-git-workflows.md ── "What branching strategy should we use?"
        └── GitFlow, trunk-based, release management

Each module is self-contained — jump to any section directly. Cross-module references are marked with 🔗.

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Tools Referenced

Tool	Install	Purpose
git ≥ 2.39	git-scm.com	Version control core
gh CLI	brew install gh · winget install GitHub.cli	GitHub from terminal
VS Code + GitHub extension	Via VS Code marketplace	In-editor code review
GitHub Desktop	desktop.github.com	GUI option
jq	brew install jq	JSON processing for API work

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Conventions Used in This Guide

Callout	Meaning
> **Note**	General information worth knowing
> **Tip**	A practical shortcut or best practice
> **Warning**	Action could cause data loss or problems
> **Danger**	Destructive — requires explicit understanding

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Content verified against GitHub documentation as of 2025. Open an issue for corrections.