I’ve recently started playing around with Supabase coming from Firebase and I like it. I’m leaning towards fully migrating because of its Postgres db which I think is a plus. But one thing I can’t find a solution to is how to convert an anonymous user to a non-anonymous one by linking it to a Google account.

I already have both Google sign-in set up using google_sign_in, and anonymous sign-in working but I’m confused as to how to merge both.

I have manual linking enabled but running this from an anonymous user:

await supabase.auth.linkIdentity(OAuthProvider.google);

throws:

AuthException(message: Unsupported provider: missing OAuth secret, statusCode: 400)

I can’t use signInWithIdToken() to link an anonymous account to google because it creates a brand new user from scratch. The user id needs to be retained because there may already be data from it:

  ...
  // BAD: Creates new user with new id
  final supabase = Supabase.instance.client;
  return supabase.auth.signInWithIdToken(
    provider: OAuthProvider.google,
    idToken: idToken,
    accessToken: accessToken,
  );

Where exactly do I get the OAuth secret and should I be using signInWithOAuth() instead of signInWithIdToken() for google accounts? Appreciate the help guys.