How does a mobile app authenticate with a backend API if the user signs in through social logins?

Question

I\'m trying to understand the basic organizations and login flow between social logins on a mobile app and how that app requests resources from a backend flask api.

If t

Answer 1

I suggest you to first read about single sign-on mechanisms:

https://en.wikipedia.org/wiki/Single_sign-on

Then you can read about OAuth2 which is used by Facebook for SSO from here

https://oauth.net/2/

https://www.digitalocean.com/community/tutorials/an-introduction-to-oauth-2

Simply you are correct, when user signs-in on Facebook, the backend will get token from Facebook that is used for authentication/ authorization of that user.