Cheat Sheet

Cheat Sheet

Keep this page bookmarked! Here’s a quick reference for everything you learned.

Terminal / Command Line

Navigation

Command	What It Does	Example
cd folder	Go into a folder	cd my-project
cd ..	Go up one folder	cd ..
pwd (Mac) / cd (Win)	Show current location	pwd
ls (Mac) / dir (Win)	List files	ls
mkdir name	Create a folder	mkdir my-project

Opening Terminal

• Windows: Win + R, type cmd, press Enter
• Mac: Cmd + Space, type Terminal, press Enter

GitHub Desktop

Creating a New Repository

1. File → New Repository (or Ctrl+N / Cmd+N)
2. Fill in name, description, and local path
3. Check “Initialize with a README”
4. Click “Create Repository”

Daily Workflow

1. Make changes in your code editor and save
2. Open GitHub Desktop - changes appear in “Changes” tab
3. Review changes - click files to see what changed
4. Write summary - describe what you changed
5. Commit to main - click the button
6. Push origin - click the button at top

Publishing to GitHub

1. Click “Publish repository” button
2. Uncheck “Keep this code private” (for GitHub Pages)
3. Click “Publish repository”

Useful Actions

Action	How To Do It
View on GitHub	Repository → View on GitHub
Open in editor	Right-click repo → Open in Visual Studio Code
Discard changes	Right-click file → Discard changes
See history	Click “History” tab
Pull latest	Repository → Pull
Clone a repo	File → Clone Repository

Claude Code

Basic Commands

# Start Claude Code
claude

# Exit Claude Code
exit
# or press Ctrl+C

Inside Claude Code

Command	What It Does
/help	Show available commands
/clear	Clear conversation
Type normally	Chat with Claude

Useful Prompts

# Create a project
Create a [type] website with [features]

# Fix something
The [feature] isn't working. Can you check why?

# Explain something
Can you explain what [code/concept] does?

# Change something
Can you change [feature] to [new behavior]?

Node.js / npm

# Check Node version
node --version

# Check npm version
npm --version

# Install a package globally
npm install -g package-name

# Install project dependencies
npm install

# Run a script from package.json
npm run scriptname

# Start a local server
npx serve
# or
npm install -g serve && serve

Local Testing

Python Server

# Python 3
python -m http.server 8000

# Python 2
python -m SimpleHTTPServer 8000

# Then open: http://localhost:8000

Node Server

npx serve
# or
npm install -g serve && serve

Browser Developer Tools

• Windows: F12 or Ctrl + Shift + I
• Mac: Cmd + Option + I

Hard Refresh (Clear Cache)

• Windows: Ctrl + Shift + R
• Mac: Cmd + Shift + R

GitHub Pages

Setup Steps

1. Go to repository Settings
2. Click Pages in sidebar
3. Set Source to Deploy from a branch
4. Select main branch, / (root) folder
5. Click Save

Your URL Format

https://USERNAME.github.io/REPO-NAME/

Claude API

Installation

npm install @anthropic-ai/sdk

Basic API Call

import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic({
  apiKey: process.env.ANTHROPIC_API_KEY,
});

const message = await client.messages.create({
  model: "claude-sonnet-4-20250514",
  max_tokens: 1024,
  messages: [{ role: "user", content: "Hello!" }],
});

console.log(message.content[0].text);

PostHog Analytics

Quick Setup

Add before </head>:

<script>
  !function(t,e){/*...PostHog snippet...*/}
  posthog.init('YOUR_KEY', {api_host: 'https://app.posthog.com'})
</script>

Track Custom Events

// Track event
posthog.capture('event_name');

// Track with data
posthog.capture('event_name', { key: 'value' });

// Opt out
posthog.opt_out_capturing();

// Opt in
posthog.opt_in_capturing();

Keyboard Shortcuts

Terminal

Shortcut	Action
Ctrl + C	Stop current command
Ctrl + L	Clear screen
↑ / ↓	Previous/next command
Tab	Auto-complete

Browser

Shortcut	Action
F5 or Cmd/Ctrl + R	Refresh
Cmd/Ctrl + Shift + R	Hard refresh
F12 or Cmd + Option + I	Developer tools
Cmd/Ctrl + U	View source

File Structure Basics

Typical Web Project

my-project/
├── index.html      # Main page
├── styles.css      # Styling
├── script.js       # JavaScript
├── images/         # Image files
│   ├── logo.png
│   └── photo.jpg
└── .gitignore      # Files Git should ignore

.gitignore Template

# Dependencies
node_modules/

# Environment
.env

# System files
.DS_Store
Thumbs.db

# Build output
dist/
build/

Quick Troubleshooting

Problem	Solution
”command not found”	Restart terminal, check installation
Git push rejected	Run git pull first
CSS not loading	Check <link> path, hard refresh
JS not working	Check browser console for errors
GitHub Pages 404	Wait 5 min, check index.html exists
API error 401	Check API key is correct

Helpful Links

• GitHub Docs
• Claude Code Documentation
• Anthropic API Reference
• PostHog Docs
• MDN Web Docs (HTML/CSS/JS reference)

View Glossary →