Install Crystal in Claude Code

What you need first

• Claude Code, installed.
• Nothing else: the server runs on its publisher's machines and Claude Code connects to it.

Steps

1. Run this in a terminal, in the project folder. It adds the server for you in that project; put --scope user after claude mcp add to have it in every project.

claude mcp add --transport http crystal https://crystal-api-118881845105.us-east5.run.app/mcp

2. Start Claude Code and type /mcp: the server is listed with its state.

Check it worked

Ask Claude Code: List the tools of crystal.

If it does not start

401 Unauthorized

The endpoint wants a sign-in or a key. Sign in when Claude Code asks.