react native – Expo Google OAuth with expo-auth-session: redirect_uri_mismatch and flowName=GeneralOAuthFlow when using auth.expo.io

I’m building an Expo React Native app and trying to implement Google Sign-In using
`expo-auth-session` and `expo-auth-session/providers/google`.

Environment:
– React Native (Expo Router)
– Running in Expo Go on iOS
– Google OAuth client IDs created in Google Cloud:
– Web application
– iOS
– Android

import { AntDesign } from '@expo/vector-icons';
import AsyncStorage from '@react-native-async-storage/async-storage';
import * as Google from 'expo-auth-session/providers/google';
import { useRouter } from 'expo-router';
import * as WebBrowser from 'expo-web-browser';
import React, { useCallback, useEffect, useState } from 'react';
import { Alert, Button, Pressable, Text, View } from 'react-native';

import IconFacebook from '../../../icons/IconFacebook';
import IconGoogle from '../../../icons/IconGoogle';

WebBrowser.maybeCompleteAuthSession();

export default function LoginScreen() {
const router = useRouter();
const [, setUserInfo] = useState(null);

const redirectUri = '

const [request, response, promptAsync] = Google.useAuthRequest({
expoClientId:
'8263....apps.googleusercontent.com',
iosClientId:
'8263...apps.googleusercontent.com',
androidClientId:
'8263332....apps.googleusercontent.com',
webClientId:
'8263332....apps.googleusercontent.com',
scopes: ['profile', 'email'],
redirectUri,
});

useEffect(() => {
console.log('Google redirectUri =', request?.redirectUri);
}, [request]);

// ...fetchUserInfo + UI omitted for brevity
}

On the Google Cloud side, my Web application client with ID:
'8263332....apps.googleusercontent.com'

has this Authorized redirect URI configured:

So I expect that, when running in Expo Go with expoClientId/webClientId, the OAuth request will use that web client and redirect URI.

However, when I start the login flow and log the generated request, I see this:
OAuth Request: {
redirectUri: "",
request: {
clientId: "826333210617-dogrjmu5121isqo1gdnblogr23j6qh6b.apps.googleusercontent.com", // <-- iOS client ID
redirectUri: "",
responseType: "code",
scopes: ["profile", "email", "openid", ...],
url: "
redirect_uri=https%3A%2F%2Fauth.expo.io%2F%40trieuman2705%2Fbkoo&
client_id=826333210617-dogrjmu5121isqo1gdnblogr23j6qh6b.apps.googleusercontent.com
&response_type=code&state=...&scope=..."
}
}

And in the browser I get this error page from Google:
Error 400: redirect_uri_mismatch
(Details mention flowName=GeneralOAuthFlow, but the main message is redirect_uri_mismatch)

So Google is seeing:
client_id = iOS client ID
redirect_uri =

but that redirect is configured for the Web client, not for the iOS client. I’m confused about why expo-auth-session is picking the iOS client ID for this flow when I’m running in Expo Go and I’ve also provided expoClientId/webClientId.