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Installation

Get Claude Code up and running on your system.

This page walks you through installing Claude Code, authenticating, and verifying everything works. The process takes about 5 minutes.

Requirements​

Before you begin, make sure you have:

  • Node.js 18+ (for npm installation)
  • Claude Pro or Max subscription, or direct Anthropic API access
  • Supported OS: macOS, Linux, Windows (via WSL recommended)

Installation Methods​

Choose the method that matches your setup. npm is recommended for most users:

npm (Global)​

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

Homebrew (macOS)​

brew install claude-code

Direct Download​

Download binaries from the GitHub releases.

Authentication​

Claude Code needs to authenticate to use Claude's API. There are two ways to do this:

Option 1: OAuth (recommended) — After installation, start Claude Code:

claude

On first run, Claude Code will open a browser for OAuth authentication. Log in with your Claude Pro/Max account. This is the easiest method.

Option 2: API Key — Set your API key as an environment variable:

export ANTHROPIC_API_KEY="your-api-key"
claude

This method is useful for CI/CD environments or if you prefer not to use OAuth.

Verify Installation​

Make sure everything is working:

claude --version
claude --help

Model Selection​

Claude Code supports multiple models. Each has different strengths:

ModelBest For
Sonnet 4.5Default, balanced speed/quality — good for most tasks
Opus 4.5Complex tasks, planning — use when you need deeper reasoning
HaikuQuick tasks, lower cost — fast responses for simple operations

Switch models during a session with /model or configure a default in settings.

Next Steps​