Installing Claude Code

Claude Code is a CLI: an agent that runs in your terminal and has access to your project's files. Before you can use it, you need to get it on your machine. This lesson will walk you through from download to the first claude --version that responds.

Machine prerequisites

You need Node.js 18 or higher. First, check what you have.

$node --version

If you see command not found or a version lower than 18, install Node from nodejs.org before continuing.

Installing Claude Code

One command, installed globally.

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

Verifying it responds

$claude --version

First launch

$claude

The first time, Claude Code will ask you to authenticate. Follow the on-screen instructions: a link to open in your browser, a code to paste back. Once done, you land in a chat interface.