I'm evaluating whether to use Ionic's cloud Auth service and it seems like it's relatively easy to implement client-side, where you can check this.auth.isAuthenticated. You can also set the user info from the client side as well.
However, if I want to do check their identity server-side, such as check that a user is authenticated when they call my custom api to post a comment - how can I get some sort of token (preferably a JWT token) that I can use to validate their identity server-side? Assuming we are using email/password authentication.
Also - using their send notification on a user's birthday example, how can I query the user data in ionic cloud's database to say find all users who have a birthday today. Can I export out the user data in any way if I want to migrate away in the future?
You should implement a JWT authentication service server side. In other words when the user is authenticated, the app can send a JWT token to the server which should be evaluated to trust the remote user. For more info reads: https://docs.ionic.io/services/auth/custom-auth.html A php example here: https://github.com/driftyco/custom-auth-examples/tree/master/php
Regards from Italy