How do I install Claude Code on Mac or Windows?

Install Anthropic's Claude Code command-line app, then run claude and complete its sign-in. Codus can use it for quadrants and Brains. Installing the separate Claude desktop app alone is not the same setup.

Before you start

You need access to Claude Code through an authentication method supported by Anthropic. Your Codus seat does not include it. If your organisation manages your account, check its access policy rather than creating another personal subscription.

Install the command-line app

1. On Mac, open Terminal and run:

   curl -fsSL https://claude.ai/install.sh | bash
   

2. On Windows, open PowerShell and run:

   irm https://claude.ai/install.ps1 | iex
   

Use the command for your operating system. These commands come from Anthropic's official setup guide. Follow that guide if your organisation requires another installation method.

3. Open a new terminal and run claude --version.
4. Run claude, follow the account sign-in prompts and return after browser approval.

If the program is not found, follow the installer's PATH instructions. Do not repeatedly append shell settings without checking the message. On Windows, WSL and native PowerShell are different installation environments.

Start Claude in Codus

1. Reopen Codus if it was running before installation.
2. Select Claude in the Brain, or start → Claude → boot project in a project quadrant.
3. Read first-use trust and permission prompts. Approve only the intended folder and recognised tools.
4. If a terminal prompt offers choices, use its arrow keys and Enter.

How do I know it worked?

Claude opens signed in and accepts your message in Codus. A browser sign-in delay is an authentication issue, not proof that installation failed. For a missing command, see Claude Code is not installed.