/oauth2/callback . For now I work around this by manually patching the library, but a more robust solution is probably warrented.authClient.useSession to get the state while the user is signing in. And indeed when I call authClient.signIn.oauth2 I get the login modal on ios (APP wants to use URL to Sign In). However, the isPending field of the session quickly toggles to true (expected) and then just as quickly toggles to false, even though I haven't even had the time to click on the modal (unexpected). This is odd, I'd expect isPending to stay true until either the sign in is completed, errored or aborted.callbackURL does not work within the app, it just stays on the same page.