Installing Claude Code and Its Dependencies

Installing Claude Code and Its Dependencies

This lesson walks you through installing Claude Code and everything you need to start coding with AI from your terminal.

Step 1: Install Node.js

Claude Code requires Node.js 18 or later. Check your current version:

node --version

If you need to install or update Node.js:

• macOS: brew install node or download from nodejs.org
• Windows: Download the installer from nodejs.org or use winget install OpenJS.NodeJS
• Linux: Use your package manager or nvm for version management

# Using nvm (recommended for version management)
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.0/install.sh | bash
nvm install 22
nvm use 22

Step 2: Install Claude Code

Install Claude Code globally using npm:

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

Verify the installation:

claude --version

Step 3: Configure Your API Key

Claude Code needs an Anthropic API key. Get yours from the Anthropic Console (console.anthropic.com):

# Set your API key
export ANTHROPIC_API_KEY="sk-ant-your-key-here"

# Add to your shell profile for persistence
echo 'export ANTHROPIC_API_KEY="sk-ant-your-key-here"' >> ~/.zshrc

Step 4: Your First Claude Code Session

Navigate to any project directory and start Claude Code:

mkdir radio-pulse && cd radio-pulse
claude

You are now in an interactive session. Try your first command:

> What files are in this directory?

Claude Code will execute ls (or equivalent) and report back. You are now coding with AI.

Step 5: Key Configuration Options

Claude Code has several useful configuration options:

# Set your preferred model
claude config set model claude-sonnet-4-6

# Enable verbose mode for debugging
claude config set verbose true

# Check your current configuration
claude config list

Understanding the Permission System

Claude Code asks for permission before executing potentially impactful commands. You will see prompts like:

Claude wants to execute: npm install express
Allow? (y/n/always)

• y — Allow this specific command
• n — Deny this command
• always — Allow this type of command for the rest of the session

Pro tip: In the early lessons, approve commands individually so you understand what Claude Code is doing. As you gain confidence, use "always" for routine operations.

Troubleshooting Common Issues

Key Takeaways

• Claude Code requires Node.js 18+ and an Anthropic API key
• Install globally with npm install -g @anthropic-ai/claude-code
• Start a session by running claude in any project directory
• The permission system keeps you in control of all file and command operations