I am not sure there is a timed element to preserve the auth or not.

(The left button on this individual app storage page)

If you press delete app data on Android, the auth is gone.

If you press delete app cache on Android, the auth is not gone.

(Error code : 14) For example, you sign in, delete the user at console, then try to link additional credential.

The error message when you try to take action on disappeared user is 'There is no user record corresponding to this identifier.

This confirms that the check is not continuous in the background, there are some point that it do this including when initialize the app instance when opening the game.

If you do that except while the app is open, you can indefinitely check for UID and it will not go away until you take some kind of Firebase action.

There is a step that try to sync with server and update the persistence accordingly.

If you sign in, close the app, then you go delete that user in Firebase Authentication console, then open the app and quickly check the preserved auth, you can see the UID briefly before turning into null.This maybe telling that app upgrade also preserves the auth. adb install -r the same APK) the auth is preserved. If you uninstall the app and reinstall it, the auth is gone.These are what I found from the debug app I wrote.

However I don't know if this persistence could disappear depending on time or not. I thought I must sign in again but I was wrong. 5 min read There is persistence magically built inįor example if you and then close the game, when you come back exists complete with correct UID! That UID information is there even if no internet connection.

Unity firebase sdk