This guide takes you from zero to productive with Claude Code. Whether you've never touched a terminal or you're a seasoned developer, this is your complete walkthrough.

How Claude Code Works

Claude Code is not autocomplete. It operates like a junior to mid-level engineer that can read, plan, act, and validate changes across your entire project.

The Core Loop:

  • READ — Your entire codebase
  • THINK — Plan changes across multiple files
  • ACT — Edit code, run tests, commit to git
  • VERIFY — Check if changes actually work
Claude Code works end-to-end across your project, not just on single files.

The /init Command and Project Memory

Running /init creates a CLAUDE.md file in your project root.

This file acts as:

  • Your project's long-term memory
  • Persistent instructions Claude reads every session

Write it once. Never explain your project again.

What to Include in CLAUDE.md

# Project Overview
Brief description of what this project does.

# Tech Stack
- Frontend: React / Next.js / etc.
- Backend: Node / Python / etc.
- Database: Supabase / Postgres / etc.

# Common Commands
- Start dev server: `npm run dev`
- Run tests: `npm test`
- Build for production: `npm run build`

# Code Style
- Use TypeScript for all new files
- Use functional components
- Keep files under 200 lines

# Important Files
- `/src/lib/api.ts` - All API calls go here
- `/src/components/` - Reusable UI components

# Things To Avoid
- Do not modify the auth system without asking
- Do not delete any existing tests
A strong CLAUDE.md dramatically improves Claude's output and consistency.

Planning Mode

Before Claude touches your code, make it think first.

How to Enter

Shift + Tab (press twice to cycle through modes)

What Happens in Planning Mode

  • Claude asks clarifying questions
  • Claude creates a detailed implementation plan
  • Claude waits for your approval before changing anything

Always plan before execution, especially on large or risky changes.

Thinking Mode

Command: /thinking

When to Use Thinking Mode

  • Debugging tricky bugs
  • Architecture decisions
  • "Why isn't this working?" scenarios
  • Multi-step logic problems

Thinking Mode forces Claude to slow down and reason deeply. Use it when you need Claude to think harder, not faster.

Panic Buttons and Safety Controls

Don't panic. You have undo buttons.

Rewind Everything

  • Press Esc twice
  • Or type /rewind

Restore Options

  • Code only
  • Conversation only
  • Both

Immediate Stop

Ctrl + C — stops execution instantly

Best Practice

Always commit before big changes. Git is your safety net.

You are always in control. Nothing is irreversible.

Connect Claude Code to GitHub

Command: /install-github-app

What This Enables

You can now interact with Claude directly inside GitHub issues and pull requests.

Examples:

  • @claude fix this bug
  • @claude review this PR
  • @claude implement this feature

Claude becomes a collaborative coding partner inside GitHub, not just the terminal.

Start Building: Your First Session

First Session Checklist

  1. cd your-project
  2. Run claude
  3. Run /init
  4. Ask: "What does this codebase do?"
  5. Give Claude your first task

You can go from zero to productive in minutes.

Claude Code Cheat Sheet

Advanced Tips (Bonus)

Use Git Worktrees for Parallel Tasks

Run multiple Claude Code sessions on different features simultaneously:

git worktree add ../project-feature-a feature-a
cd ../project-feature-a && claude

External Memory Files

For long projects, create these files to persist context:

At the start of each session, tell Claude to read these files. At the end, tell Claude to update them.

The GSD (Get Shit Done) Framework

A free framework that gives you structured prompts and prevents context window blowouts:

npx get-shit-done-cc

Repository: https://github.com/glittercowboy/get-shit-done

Useful Plugins

Common Mistakes to Avoid

  • Don't skip /init — Claude needs context to be effective
  • Don't let Claude run wild — Use Planning Mode for anything complex
  • Don't forget to commit — Git is your undo button for everything
  • Don't bloat your CLAUDE.md — Keep it focused on what Claude gets wrong