expo-google-app-auth vs expo-google-sign-in

I am trying to build a standalone application that will use google authorization. For this purpose I was traversing the expo-google-app-auth documentation.

Everything was going perfect until Server side APIs section. It is stated:

For Standalone apps You will need to use expo-google-sign-in to perform server side authentication outside of the Expo client.

But the server side token validation is not stated clearly in expo-google-sign-in documentation.

So the question is, why do I need to use the expo-google-sign-in to perform server side authentication for standalone applications? (Why just a call like below - which works fine when in for Expo client experience - will not work?)

fetch(` https://www.googleapis.com/userinfo/v2/me?oauth_token=${token}&fields=${permissions}`)

Addenda

  • It seems expo-google-app-auth gets valid tokens for standalone applications as well. So no thechnical problem. Hence post moved under the docs section.
  • Maybe some additional clarification in Server side APIs section can be good.