Expo

The library ships an Expo config plugin (app.plugin.js) that writes the native config for you. It is not supported in Expo Go (see why): use a development build (npx expo prebuild / npx expo run:ios / npx expo run:android, or EAS Build). The New Architecture must be enabled (the default since SDK 52).

Setup

npx expo install react-native-oauth-essentials

Add the plugin to app.json (or app.config.js) with only the features you use:

{
  "expo": {
    "plugins": [
      [
        "react-native-oauth-essentials",
        {
          "google": {
            "iosClientId": "1234-abcd.apps.googleusercontent.com",
            "webClientId": "5678-efgh.apps.googleusercontent.com"
          },
          "appleSignIn": true,
          "webCredentialsDomains": ["example.com"]
        }
      ]
    ]
  }
}

Then regenerate the native project: npx expo prebuild (or npx expo run:ios / npx expo run:android, which run it).

Options

All options are optional.

Option	Type	iOS	Android
`google`	`true \| { iosClientId?: string; webClientId?: string }`	Info.plist: the reversed iOS client id URL scheme in `CFBundleURLTypes` (not added twice), `GIDClientID` = iOS client id and, when a web client id is found, `GIDServerClientID` = web client id	AndroidManifest: `<meta-data android:name="com.oauthessentials.GOOGLE_WEB_CLIENT_ID">` = web client id
`appleSignIn`	`boolean`	Entitlements: `com.apple.developer.applesignin` = `["Default"]`	Nothing
`webCredentialsDomains`	`string[]`	Entitlements: `webcredentials:<domain>` for each domain in `com.apple.developer.associated-domains`, merged with the existing ones (used by passkeys and saved passwords)	Nothing

`google`

The client ids come from the plugin options or, when missing, from the Firebase config files set in the Expo config. Ids passed to the plugin win over the files.

iOS client id: written with its URL scheme, which is the client id split by ., reversed and joined: 1234-abcd.apps.googleusercontent.com becomes com.googleusercontent.apps.1234-abcd. When none is found, prebuild only warns and leaves Info.plist unchanged (fine if you use Google on Android only), and Google Sign-In on iOS rejects with CONFIGURATION_ERROR unless you pass { iosClientId } in code.
Web client id: prebuild only warns when none is found. Android sign in then rejects with CONFIGURATION_ERROR (unless you pass { webClientId } in code), and the iOS idToken audience is the iOS client id.

Because the ids are in Info.plist and AndroidManifest, the native side reads them from there, so call the methods without client ids:

import { googleSignIn } from 'react-native-oauth-essentials';

const result = await googleSignIn(); // or googleSignIn({ mode: 'button' })

Passing { iosClientId, webClientId } in code also works and wins over the config. See Google Sign-In and the Google OAuth setup to create the client ids.

Using Firebase config files

With Firebase, set google: true and point the Expo config to the Firebase files: the plugin reads the ids from them.

{
  "expo": {
    "ios": {
      "bundleIdentifier": "com.example.app",
      "googleServicesFile": "./GoogleService-Info.plist"
    },
    "android": {
      "package": "com.example.app",
      "googleServicesFile": "./google-services.json"
    },
    "plugins": [["react-native-oauth-essentials", { "google": true }]]
  }
}

ios.googleServicesFile: CLIENT_ID is the iOS client id.
android.googleServicesFile (google-services.json): the web client id is the OAuth client with client_type 3, and the iOS client id (when the plist does not give one) is the client_type 2 client whose ios_info.bundle_id matches ios.bundleIdentifier.

When Google is enabled as a sign-in provider in Firebase Authentication (and the SHA-1 is added to the Firebase Android app), Firebase creates the web, Android and iOS OAuth clients itself; download the config files again after that so they contain the ids.

`appleSignIn`

Adds the Sign in with Apple entitlement. You still need to enable Sign in with Apple on the App ID in the Apple Developer portal (EAS Build can sync capabilities for you). See Apple Sign-In.

`webCredentialsDomains`

Adds webcredentials: Associated Domains, needed by passkeys and for iOS to match saved passwords. Your server must still serve https://<domain>/.well-known/apple-app-site-association (and assetlinks.json for Android passkeys).

Android

Google needs the web client id, written by the google option as manifest meta-data (or passed in code). The Android client id is never used directly: it only has to exist in Google Cloud with your package name and SHA-1 fingerprints.
The library manifest already registers the CustomTabsActivity that handles OAUTH_REDIRECT_URI (<applicationId>://oauth/callback).

Why it does not run in Expo Go

Expo Go is a prebuilt app from the stores that only contains the native modules of the Expo SDK. Your JavaScript is loaded into it, but native code (the library's Swift and Kotlin, the GoogleSignIn SDK) cannot be added at runtime, and its URL schemes, entitlements and bundle id belong to Expo Go, not to your app. Use a development build (npx expo run:ios / npx expo run:android or eas build --profile development).

In Expo Go, importing the library throws:

react-native-oauth-essentials does not work in Expo Go, which only contains the Expo SDK native code. Create a
development build instead: `npx expo run:ios` / `npx expo run:android` or `eas build --profile development`.

Setup​

Options​

google​

Using Firebase config files​

appleSignIn​

webCredentialsDomains​

Android​

Why it does not run in Expo Go​