Lesson 5 of 8

Install Node.js and your AI CLI

Two commands and you're ready to talk to your AI agent.

~10 min to complete

With Homebrew in place, installing Node.js and your chosen coding CLI is straightforward. You'll run two commands.

1. Install Node.js (everyone does this)

Node.js is what runs JavaScript code on your computer. Both CLIs use it, and many of the apps you'll build will too.

brew install node

This takes 1–3 minutes. When you see the % prompt again, it's done.

node --version

Should print v20.x.x or higher.

2. Install your coding CLI

Pick one of the two options below — the one you decided on in Lesson 2. If you're undecided, pick Claude Code: its Plan Mode is the most beginner-friendly default.

Option A — Claude Code

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

This downloads and installs the Claude Code command-line tool. It takes about a minute.

Verify it installed:

claude --version

Start it for the first time:

claude

This opens Claude Code and walks you through logging in with your Anthropic account. Follow the on-screen prompts — it will open your browser to complete authentication. If you have a Claude Pro or Max subscription, sign in with that. Otherwise, sign in to your Anthropic API account.

Claude Code running in Terminal, showing the welcome banner with the Claude Code mascot, the active model (Opus 4.7, 1M context), the Claude Max plan, the project directory, a 'Tips for getting started' panel, and an empty input box at the bottom. — Claude Code on first run. The welcome banner confirms you're logged in and ready to prompt.

When you're done and back in Terminal, Claude Code is ready. Type /exit and press Enter to close it for now — the next lesson uses it to finish the rest of the setup.

Option B — Codex CLI

npm install -g @openai/codex

This downloads and installs the Codex command-line tool.

Verify it installed:

codex --version

Start it for the first time:

codex

This opens Codex CLI and walks you through logging in. The simplest path is Sign in with ChatGPT — your browser will open and prompt you to authorize. If you don't have ChatGPT Plus or higher, you can paste an OpenAI API key from platform.openai.com instead.

OpenAI Codex CLI running in Terminal, showing the version banner, the active model (gpt-5.5 medium), the project directory, a tip about GPT-5.5, and an empty input box at the bottom. — Codex CLI on first run. The banner shows your model and project directory; the empty input box is ready for your first prompt.

When you're done and back in Terminal, Codex CLI is ready. Type /quit and press Enter to close it for now — the next lesson uses it to finish the rest of the setup.

You'll know it worked when you saw your CLI's greeting in Terminal and a prompt waiting for your input. You're now talking to an AI that can read and write files on your Mac.

Want to try both? Nothing stops you. Run both npm install commands and you'll have claude and codex both available. The rest of this course uses generic instructions like "open your CLI" so it works either way.