Is there a Google Keep API?
UPDATE: yes, Google released a public REST API for Keep. Here's the public documentation.
No there's not and developers still don't know why google doesn't pay attention to this request!
As you can see in this link it's one of the most popular issues with many stars in google code but still no response from google! You can also add stars to this issue, maybe google hears that!
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/