I am writing an API.AI app with Google Actions (will run on google assistant and google home). The app should be able to read\add events to the user's google calendar account.
The backend is Google Cloud Functions, and I enabled the Calendar API in the developers console.
The flow the user should experience is something like this:
User: "Hey Google, when was my last meeting with Anna?"
Agent: "Your last meeting with Anna was two days ago"
User: "Set a meeting with Anna for the tomorrow"
Agent: "Ok. Meeting is set"
How should I build the authentication process to grant the app access to the calendar?