Prerequisites

Start needs three things on your system before it can run.

Node.js 18+

The agent process runs on Node. Install it however you prefer:

# Homebrew
brew install node

# Or nvm
nvm install 22

Verify with node --version.

Git

Required for file tracking, diffs, and worktree support.

brew install git

Claude CLI

Start authenticates through the Claude CLI. Install it and log in:

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

Start picks up your credentials automatically on launch.

Verify everything

When you open Start, it checks all prerequisites on the welcome screen. A green checkmark next to Claude means you're ready to go. If anything is missing, Start will tell you what to install.