Installation on macOS and Windows

Installing Claude Code takes a few minutes. Let's walk through it.

macOS

Claude Code is distributed as an npm package. If you have Node.js 18+ installed, you can install it globally:

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

Verify the install:

claude --version

If you see a version number, you're good.

Authenticate

The first time you run claude, you'll be prompted to log in. Two options:

• Claude Pro / Max subscription: log in with your Anthropic account (recommended — no API cost per message)
• API key: set ANTHROPIC_API_KEY in your shell profile

export ANTHROPIC_API_KEY="sk-ant-..."

Then:

cd ~/Projects/my-project
claude

Windows

Claude Code runs on Windows, but the best experience is via WSL (Windows Subsystem for Linux). Install WSL first if you haven't:

wsl --install

Restart, open your WSL terminal (Ubuntu by default), then install Node and Claude Code inside WSL:

# Install Node (if not already)
curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
sudo apt install -y nodejs

# Install Claude Code
npm install -g @anthropic-ai/claude-code

Your projects should live inside the WSL filesystem (~/ inside WSL, not /mnt/c/) for best performance.

First-run configuration

The first time you run claude in a project, it creates a .claude/ folder and writes your preferences. You don't need to touch these files manually — Claude Code manages them.

Troubleshooting

command not found: claude — The global npm bin directory isn't in your PATH. Run npm config get prefix and add <prefix>/bin to your PATH.

Corporate network / proxy — Set HTTPS_PROXY in your shell environment before launching Claude Code.

Permission errors on install — On macOS or Linux, avoid sudo npm install -g. Instead, configure npm to use a local prefix: npm config set prefix ~/.npm-global, then add ~/.npm-global/bin to your PATH.

Next

You have Claude Code installed and authenticated. Next lesson: starting your first project.