Day 0 -- Claude Code Setup

This guide walks you through installing Claude Code on your machine and authenticating so you can start using it.

Step 1: Install Claude Code

Choose your operating system:

OS	Guide
macOS	macOS Setup
Windows	Windows Setup
Linux	Linux Setup

Follow the guide for your OS, then come back here for authentication.

Step 2: Verify Installation

After following your OS-specific guide, confirm everything is working:

node --version    # Should show v18.x or higher
claude --version  # Should show the installed Claude Code version

Step 3: Login

Run claude in your terminal. On first launch, it will ask you to choose a login method.

Method 1: Subscription (Claude Pro / Max)

• Select Claude.ai account
• Browser opens -- sign in and authorize
• Return to terminal, you're logged in

Method 2a: API Key (Team Invite)

Your team admin invites you from the Anthropic dashboard.

• You receive an invite email -- accept it and create your Anthropic account
• Run claude in your terminal
• Select Anthropic API Key
• Your key is auto-generated on the dashboard -- no manual setup needed
• Claude Code starts working immediately

Method 2b: API Key (You have the key)

If someone shared the key with you (via Slack, email, etc.) or you created your own:

• Run claude in your terminal
• Select Anthropic API Key
• Paste your key (starts with sk-ant-)
• The key is stored permanently -- you won't be asked again

What's Next?

Once you are logged in, you are ready to start using Claude Code. Type claude in any project directory to begin an interactive session.