@crown-dev-studios/google-auth

React Native Google sign-in that returns a one-time server authCode instead of doing token exchange on-device. Use this when your backend owns Google OAuth and your mobile app only needs to start the flow and hand the code to your server.

What It Includes

• Native Google auth-code sign-in for iOS and Android
• Scope management helpers for incremental consent flows
• Expo config plugin for wiring the native setup in prebuilt apps
• A small JS API surface with no opinion about your backend

Install

npm install @crown-dev-studios/google-auth

Peer dependency:

npm install react-native

If you are using Expo, use a custom dev client or a prebuilt app. Expo Go is not supported because this package ships native code.

Quick Start

import {
  configureGoogleAuth,
  signInWithGoogle,
} from '@crown-dev-studios/google-auth'

await configureGoogleAuth({
  iosClientId: 'your-ios-client-id.apps.googleusercontent.com',
  webClientId: 'your-web-client-id.apps.googleusercontent.com',
  scopes: ['openid', 'email', 'profile'],
})

const { authCode, grantedScopes } = await signInWithGoogle()
// Send authCode to your server for exchange.

API

configureGoogleAuth(config)

Configures the native Google SDKs.

await configureGoogleAuth({
  iosClientId: 'ios-client-id',
  webClientId: 'web-client-id',
  scopes: ['openid', 'email', 'profile'],
})

Notes:

• webClientId is always required.
• iosClientId is required on iOS.
• If scopes is omitted, the default is ['openid', 'email', 'profile'].

signInWithGoogle()

Starts Google sign-in and resolves to:

type GoogleAuthResult = {
  authCode: string
  grantedScopes: string[]
}

updateGoogleScopes(request)

Requests additional scopes or replaces the previously granted set.

import { updateGoogleScopes } from '@crown-dev-studios/google-auth'

await updateGoogleScopes({
  scopes: ['https://www.googleapis.com/auth/calendar.readonly'],
  mode: 'add',
})

mode:

• 'add' adds new scopes to the current session
• 'replace' replaces the current set

getGoogleGrantedScopes()

Returns the scopes currently known to be granted for the active session.

revokeGoogleAccess()

Disconnects the app from the Google account and revokes the granted access.

signOutGoogle()

Signs out locally without necessarily revoking previously granted access.

Expo Config Plugin

Add the plugin in app.config.ts or app.json:

export default {
  plugins: [
    [
      '@crown-dev-studios/google-auth/plugin',
      {
        iosClientId: 'your-ios-client-id.apps.googleusercontent.com',
        webClientId: 'your-web-client-id.apps.googleusercontent.com',
      },
    ],
  ],
}

The plugin requires both iosClientId and webClientId. If either is missing, native Google Sign-In configuration is skipped.

Typical Use Case

1. Configure the package at app startup.
2. Call signInWithGoogle().
3. Post the returned authCode to your backend.
4. Exchange the code server-side and continue your auth flow.

This package intentionally does not store access tokens or refresh tokens for you.