Add the server by URL and sign in from your client. No key to copy, and you can revoke the connection from your account at any time.
claude mcp add --transport http pointless https://pointless-agent-service-7bjvrfi3aa-uc.a.run.app/mcp
Then run /mcp and sign in.
Settings → Connectors → Add custom connector, and paste that URL. Leave the client secret blank.