I have been waiting to see if Google would open a Keep API. When I discovered Google Tasks, and saw that it had an Android app, web app, and API, I converted over to Tasks. This may not directly answer your question, but it is my solution to the Keep API problem.
Tasks doesn't have a reminder alarm exactly like Keep. I can live without that if I also connect with the Calendar API.
https://developers.google.com/google-apps/tasks/