Claude Code — Getting Started Guide

What Is Claude Code?

Claude Code is Anthropic’s agentic coding tool. It reads your codebase, edits files, runs commands, and integrates with your dev tools — and it now runs on several surfaces: the terminal CLI, VS Code and JetBrains extensions, a desktop app, and the browser at claude.ai/code. Same engine everywhere, so your CLAUDE.md, settings, and MCP servers carry across surfaces.

Most surfaces require a Claude subscription (Claude Code is included in all paid plans) or an Anthropic Console account for pay-as-you-go API billing.

Installation

From the official docs, current as of 2026-09-09:

# macOS, Linux, WSL — native installer (recommended)
curl -fsSL https://claude.ai/install.sh | bash

# Windows PowerShell
irm https://claude.ai/install.ps1 | iex

# macOS via Homebrew
brew install --cask claude-code

# Windows via WinGet
winget install Anthropic.ClaudeCode

Native installs auto-update in the background. Homebrew and WinGet installs don’t — upgrade manually. On native Windows, install Git for Windows so Claude Code can use the Bash tool.

Basic Usage

# Start Claude Code in your project directory
cd my-project
claude

# Give it a task
> Add authentication using NextAuth with GitHub OAuth

You’ll be prompted to log in on first use. If ANTHROPIC_API_KEY is set, it asks you to approve the key instead.

Claude Code will:

1. Read your codebase to understand the structure
2. Plan the implementation
3. Create/modify files
4. Run tests
5. Fix any failures
6. Present a summary of changes

It also works non-interactively, Unix-style:

# One-shot task
claude "write tests for the auth module, run them, and fix any failures"

# Pipe input in CI
tail -200 app.log | claude -p "Summarize any anomalies"

Setting Up CLAUDE.md

Create a CLAUDE.md file in your project root to teach Claude Code your conventions. It loads at the start of every session:

# Project: My SaaS App

## Stack
- Next.js 15 (App Router)
- TypeScript 5.6
- Prisma + PostgreSQL
- Tailwind v4

## Conventions
- Use server components by default
- Data fetching via tRPC
- Tests with Vitest
- No default exports

## Commands
- `npm run dev` — start dev server
- `npm test` — run tests
- `npm run lint` — run ESLint

Claude Code also builds auto memory as it works, saving learnings across sessions without you writing anything.

→ Browse our CLAUDE.md templates:

• CLAUDE.md for TypeScript
• CLAUDE.md for Next.js
• CLAUDE.md for Python

Beyond the Basics

• MCP — connect external tools (Jira, Slack, databases) with MCP servers
• Skills — package repeatable workflows your team can share
• Hooks — run shell commands before/after actions, e.g. auto-format on every edit
• Sub-agents — spawn parallel agents on different parts of a task
• Routines — schedule recurring cloud tasks like morning PR reviews

Claude Code vs Cursor

→ Full comparison

Related

• Vibe Coding Guide
• Context Engineering
• Claude — Full Claude overview
• AI Coding Tools Compared