As part of my project, I need to send both the anonymous and the email access token to the backend.
Unfortunately, after the user logs in through the Firebase-UI, Firebase only returns the token for the newly logged-in user.
I could of course store the anonymous token, but it's possible that that would expire in the meantime. So is there a way to keep both the anonymous user as well the signed-in email user and get their token?

CodePudding user response：

I need to send both the anonymous and the email access token to the backend.

You can do that, but separately. You cannot have a single user logged in with two different providers at the same time.

Unfortunately, after the user logs in through the Firebase-UI, Firebase only returns the token for the newly logged-in user.

That's the expected behavior. Since you can only read the token of the currently logged-in user.

but it's possible that that would expire in the meantime

The anonymous auth token that identifies the account doesn't persist when the user logs out, and unfortunately, there is no way to reclaim that token for the user. Firebase anonymous authentication helps you create and use temporary accounts to authenticate your users in your application. These temporary anonymous accounts can be used to allow users who haven't yet signed up for your app. If such an anonymous user decides later to sign up for your application, you can link their sign-in credentials to the anonymous account.

So is there a way to keep both the anonymous user as well the signed-in email user and get their token?

No.