Module 0 of 12·5 min

Setup & Installation

Installing Claude Code, first-time configuration, and verifying everything works.

Test Your Understanding

Knowledge Check

Multiple-choice quiz covering the key concepts from this module.

This module gets you from zero to a working Claude Code installation. If you already have Claude Code running, skip to the next module.

Requirements

Requirement	Detail
Operating system	macOS, Linux, or Windows (via WSL2)
Node.js	v18 or later
RAM	4GB minimum (8GB recommended)
Anthropic account	For authentication

Info

Windows users: Claude Code runs natively on macOS and Linux. On Windows, you'll need WSL2 (Windows Subsystem for Linux). Install WSL2 first, then follow the Linux instructions inside your WSL terminal. Some VS Code terminal rendering issues exist on Windows — if you hit display glitches, try using an external terminal like Windows Terminal instead.

Installation

Two options — pick whichever suits your setup:

bash

# Option A: npm (works everywhere with Node.js)
npm install -g @anthropic-ai/claude-code
 
# Option B: Homebrew (macOS)
brew install --cask claude-code

Verify the installation:

bash

claude --version

You should see a version number. If you get "command not found", make sure your npm global bin directory is in your system PATH.

How do you install Claude Code?

Authentication

This is where people get tripped up, so read carefully.

There are two ways to authenticate, and they have different billing implications:

Option 1: Claude Subscription (Recommended for Teams)

If your company has a Claude Team or Enterprise plan, or you have a personal Max or Pro subscription:

Run claude in your terminal
Select "Claude.ai account" when prompted
Follow the browser-based OAuth flow

Usage counts against your subscription's limits. No per-token charges — but you may hit usage caps during busy periods.

Option 2: Anthropic API Key (Pay-per-Token)

If you want uncapped usage and are comfortable with pay-as-you-go:

Go to console.anthropic.com and create an API key
Run claude in your terminal
Select "Anthropic API Key" when prompted
Paste your key

Every request is billed per token. Costs vary by model — Opus is significantly more expensive than Sonnet.

Warning

The billing distinction matters. A Claude subscription gives you usage within plan limits. An API key charges per token with no cap. If you're unsure which you're using, run /cost during a session — if it shows dollar amounts, you're on API billing. Within our team, start with the company Claude subscription. If you find yourself hitting limits regularly, talk to Amadeus about API key access.

Initialise Your First Project

Navigate to a project directory and run:

bash

cd your-project
claude /init

This does two things:

Scans your codebase — reads file structure, package.json, common patterns
Creates a CLAUDE.md file — a summary of your project that Claude will reference on every request

You can (and should) edit this file afterwards. The auto-generated version is a starting point, not a finished product — we cover this in detail in the Context & Memory module.

What does claude /init do in a project directory?

Set a Budget Limit

If you're using an API key, set a safety net immediately:

bash

claude --max-budget-usd 5

This caps the current session at $5. If Claude hits the limit, it stops rather than continuing to spend. You can adjust the number as you get comfortable with typical session costs.

Verify Everything Works

Run a simple test:

bash

claude "What files are in the root of this project? List them briefly."

If Claude lists your project files, you're good to go. If you see an authentication error, double-check your auth setup. If you see a timeout, check your internet connection.

Quick Orientation

When Claude Code is running, your terminal becomes an interactive session:

You type prompts at the bottom
Claude responds with text, and may request to use tools (read files, run commands, etc.)
Permission prompts appear when Claude wants to modify files or run shell commands — you approve or reject each one
Shift+Tab cycles between permission modes (Normal → Auto-accept → Plan)

Tip

Useful commands to know from day one: /help shows all available slash commands. /model shows which AI model you're using. /cost shows token usage for the current session. /clear starts a fresh conversation.