Quick Start

Install Claude Code, authenticate, and complete your first task in under 5 minutes.

This guide gets you from zero to a working Claude Code session. You’ll install the package, sign in with your Anthropic account, and run your first task.

1. Install Claude Code

   Install the @anthropic-ai/claude-code package globally with npm.

   npm install -g @anthropic-ai/claude-code
   

   This makes the claude command available in your terminal. Node.js 18 or later is required.

   If you see a permissions error on macOS or Linux, your npm global prefix may require sudo. Consider using a version manager like nvm to avoid this.

2. Sign in to your Anthropic account

   Authenticate using the /login command. Claude Code opens a browser window for the OAuth flow.

   claude /login
   

   You can sign in with a Claude Pro or Max subscription (claude.ai) or with API usage billing via the Anthropic Console. Select the method that matches your account when prompted.

   After you authorize in the browser, Claude Code stores your credentials securely and returns you to the terminal.

3. Navigate to your project

   Change into the directory you want to work in. Claude Code uses your current working directory as the project root.

   cd my-project
   
4. Start a session

   Run claude with no arguments to open the interactive REPL.

   claude
   

   You’ll see the Claude Code prompt. You can now type tasks in plain English.

5. Run your first task

   Type a task at the prompt. Here are a few things to try:

   > Explain the structure of this codebase
   

   > Find all TODO comments and list them with their file paths
   

   > Fix the failing tests in the auth module
   

   Claude Code will read the relevant files, show you what it plans to do, and ask for your confirmation before making any changes.

Example session

Here is what a typical first interaction looks like:

$ claude

Claude Code — type a task or /help for commands

> What does the main entry point do?

I'll read the main entry point file for you.

[Reading src/main.ts...]

The main entry point sets up the CLI using Commander.js. It:
- Parses flags like --model, --verbose, and --print
- Initializes authentication and settings
- Launches the interactive REPL or processes a one-shot prompt

> Add a --version flag that prints the package version

I'll add a --version flag to src/main.ts.

[Edit src/main.ts]
  + program.version(pkg.version, '-v, --version', 'Print version number')

Apply this change? [y/n] y

Done. Run `claude --version` to test it.

Useful commands

Once you’re in a session, these slash commands are available:

Command	What it does
/help	List all available commands
/login	Switch Anthropic accounts
/doctor	Check your installation and configuration
/cost	Show token usage and cost for this session
/compact	Compress the conversation to free up context
/commit	Create a git commit for your current changes
/review	Run a code review on the current diff
/exit	End the session

Next steps

Installation

System requirements, platform notes, and troubleshooting

How it works

The tool system, permission model, and agent loop

Git workflows

Use Claude Code to commit, review, and manage PRs

MCP integrations

Connect Claude Code to external tools and data sources