Hi, we are working on getting that lifted (I'm one of the maintainers.) Right now you're best bet is to sign up for your own API key/secret and supply those via either a config file or command line arguments:

  --client_id API client_id
  --client_secret API client_secret

See https://github.com/insanum/gcalcli/issues/65#issuecomment-13... for details on how to get those.