@exclusive118/expo-firebase-cred-manager

Expo module for Firebase Auth and Android Credential Manager flows.

This package is Android-first. On iOS/web, methods throw E_UNSUPPORTED_PLATFORM (except isAvailable, which returns false).

Install

npm install @exclusive118/expo-firebase-cred-manager

Expo Plugin Setup

In app.json:

{
  "expo": {
    "plugins": [
      [
        "@exclusive118/expo-firebase-cred-manager",
        {
          "googleServicesFile": "./google-services.json"
        }
      ]
    ]
  }
}

Plugin options:

• googleServicesFile (required): path to Android google-services.json
• webClientId (optional): override Google Web OAuth client ID
• hostedDomainFilter (optional): hosted domain filter for Google button flow

If webClientId is not provided, the plugin auto-detects it from google-services.json (oauth_client entry where client_type is 3).

Usage

import {
  signInWithEmailPassword,
  signUpWithEmailPassword,
  savePasswordCredential,
  signInWithGoogleButton,
  signInWithGoogleBottomSheet,
  signOut,
  deleteCurrentUser,
  addAuthStateListener,
  clearCredentialState,
  getCurrentSession,
  isAvailable,
} from '@exclusive118/expo-firebase-cred-manager';

API return values

Most exported methods are async and return a Promise. addAuthStateListener returns a subscription object synchronously.

| Function | Resolves with | | --- | --- | | isAvailable() | Promise<boolean> | | getCurrentSession(input?) | Promise<AuthResult \| null> | | signInWithEmailPassword(input) | Promise<AuthResult> | | signUpWithEmailPassword(input) | Promise<AuthResult> | | savePasswordCredential(input) | Promise<{ saved: true }> | | signInWithGoogleButton(input?) | Promise<AuthResult> | | signInWithGoogleBottomSheet(input?) | Promise<AuthResult> | | signOut(options?) | Promise<void> | | deleteCurrentUser(options?) | Promise<void> | | addAuthStateListener(listener) | AuthStateSubscription | | clearCredentialState() | Promise<void> |

deleteCurrentUser(options?) behavior:

• clearCredentialState defaults to true
• reauthenticateIfRequired defaults to true
• webClientId/nonce are optional and used for Google reauthentication when recent login is required

Note: clearCredentialState clears provider session state in Credential Manager. It does not guarantee removal of saved passwords/passkeys.

addAuthStateListener(listener) behavior:

• Emits onAuthStateChanged whenever Firebase auth state changes.
• Listener receives { session: AuthStateSession | null }.
• session includes provider and user fields; if signed out, session is null.
• Use subscription.remove() to stop listening.

Error codes

Rejections are ExpoFirebaseCredManagerError objects (an Error plus a code field):

type ExpoFirebaseCredManagerError = Error & { code: ExpoFirebaseCredManagerErrorCode };

try {
  const session = await getCurrentSession();
} catch (error) {
  const e = error as { code?: string; message?: string };
  if (e.code === 'E_UNSUPPORTED_PLATFORM') {
    // handle Android-only behavior
  }
}

ExpoFirebaseCredManagerErrorCode values:

E_UNSUPPORTED_PLATFORM, E_INVALID_INPUT, E_NO_ACTIVITY, E_GOOGLE_WEB_CLIENT_ID_REQUIRED, E_GOOGLE_ID_TOKEN_PARSE, E_UNSUPPORTED_CREDENTIAL, E_UNEXPECTED_CREDENTIAL_TYPE, E_CANCELLED, E_INTERRUPTED, E_NO_CREDENTIAL, E_PROVIDER_CONFIGURATION, E_CUSTOM, E_UNKNOWN, E_GET_CREDENTIAL, E_CREATE_CREDENTIAL, E_NO_CREATE_OPTION, E_CLEAR_CREDENTIAL_STATE, E_AUTH_INVALID_CREDENTIALS, E_AUTH_INVALID_USER, E_AUTH_REQUIRES_RECENT_LOGIN, E_AUTH_REAUTH_REQUIRED, E_AUTH_EMAIL_ALREADY_IN_USE, E_AUTH_WEAK_PASSWORD, E_AUTH, E_ID_TOKEN_UNAVAILABLE.

Delete-specific recovery notes:

• E_AUTH_REQUIRES_RECENT_LOGIN: deleting the user requires a recent login and automatic reauthentication was disabled.
• E_AUTH_REAUTH_REQUIRED: automatic reauthentication failed (for example cancelled, no credential, mismatch, or invalid credential). Prompt sign-in and retry delete.

AuthResult shape:

type AuthResult = {
  idToken: string;
  provider: 'password' | 'google';
  isNewUser: boolean | null;
  user: {
    uid: string;
    email: string | null;
    displayName: string | null;
    photoURL: string | null;
    emailVerified: boolean;
    isAnonymous: boolean;
    creationTimestamp: number | null;
    lastSignInTimestamp: number | null;
  };
};