Password Sign-In

Using the built-in password sign-in features is much more secure than storing usernames and passwords manually. Android and iOS keep saved credentials cryptographically secure, and when synced (e.g., via Google Password Manager on Android or iCloud Keychain on Apple devices), they can be accessed across your devices. This makes signing in with a username and password take only a few seconds.

You can check more on following links:

1. Apple Support - iCloud Keychain - Details how Apple keeps passwords secure and synced across devices.
2. Google Chrome Developers - Passkeys and Google Password Manager - Explains how Google encrypts and syncs passwords and passkeys on Android and other devices.

Platform Support

iOS

• Minimum: iOS 12+
• Uses iOS Keychain Services
• Integrates with iCloud Keychain for sync across devices
• Presents native password autofill UI
• Supports AutoFill everywhere
• Matches saved passwords through the webcredentials:yourdomain.com Associated Domain (see Passkeys, or the Expo plugin webCredentialsDomains option)
• Check PASSWORD_SUPPORTED constant before using

Android

• Minimum: Android 7.0+ (API 24+)
• Uses Credential Manager API
• Integrates with Google Smart Lock for Passwords
• Can sync credentials across devices via Google account
• Presents native credential picker UI
• Supports autofill everywhere
• Requires Google Play Services: PASSWORD_SUPPORTED equals GOOGLE_PLAY_SERVICES_SUPPORTED, and the methods reject with NOT_SUPPORTED_ERROR without them
• Check PASSWORD_SUPPORTED constant before using

Introduction

Always start by calling getPassword to try retrieving saved credentials automatically. If it resolves CANCELLED or fails, show your own login UI for the user to enter their username and password. Validate these credentials on your backend, and once your backend returns the API credentials, store the same username/password using the passwordSignIn method so that future sign-ins can happen automatically. Android and iOS keep saved credentials cryptographically secure and synced across devices, making sign-in fast and safe.

Methods

getPassword(): Promise<PasswordCredentialResult | CancelledCredentialResult>

Retrieves a previously stored password credential from the device.

Parameters

This function does not take any parameters.

Returns

Promise<PasswordCredentialResult | CancelledCredentialResult>

PasswordCredentialResult:

{
  type: CredentialsType.PASSWORD;
  data: {
    username: string;                // Stored username
    password: string;                // Stored password
  };
}

• Resolves to a PasswordCredentialResult object when the user picks a stored credential.
• Resolves to { type: CredentialsType.CANCELLED, data: null } when the user dismisses it or no stored password is found, on both platforms. It never resolves false.

Migrating to 1.1

Before 1.1, Android resolved false when there was no password or on errors. Replace if (!result) / result === false checks with result.type === CredentialsType.CANCELLED. Other Android errors now reject with INVALID_RESULT_ERROR.

Error Codes

Error Code	Description	Platform
NOT_SUPPORTED_ERROR	Google Play Services not available or outdated	Android only
NO_ACTIVITY_ERROR	No Android activity context available	Android only
SIMULTANEOUS_CALL_ERROR	A previous getPassword is still pending	iOS only
INVALID_RESULT_ERROR	Invalid result from credential manager	Both

Notes

• Always check PASSWORD_SUPPORTED before calling this method
• Available on both Android (API 24+) and iOS (12+)
• Useful for retrieving credentials that were previously saved via the password manager
• Resolves CANCELLED if no credential is stored (not an error)

Example Usage (TypeScript)

import { getPassword, PASSWORD_SUPPORTED, CredentialsType } from 'react-native-oauth-essentials';

async function retrievePassword(): Promise<void> {
  if (!PASSWORD_SUPPORTED) {
    console.log('Password sign-in is not supported on this platform.');
    return;
  }

  try {
    const credential = await getPassword();

    if (credential.type === CredentialsType.CANCELLED) {
      console.log('No stored password found or the user dismissed it.');
      // Show manual login UI
      return;
    }

    if (credential.type === CredentialsType.PASSWORD) {
      console.log('Retrieved password credential');
      console.log('Username:', credential.data.username);

      // Authenticate with your backend
      await authenticateWithBackend(
        credential.data.username,
        credential.data.password
      );
    }
  } catch (error) {
    console.error('Failed to get stored password:', error);
    // Show manual login UI
  }
}

passwordSignIn(username: string, password: string): Promise<boolean>

Saves username/password credentials to the platform's credential manager.

Parameters

Name	Type	Description
username	string	The username of the account.
password	string	The password for the account.

Returns

Promise<boolean>

• Resolves to true if credentials are successfully saved (Android)
• Resolves to false if saving fails or the user declines (Android), and always on iOS, where it does nothing (it logs a warning in development): use textContentType on your inputs so iOS offers to save the password

Error Codes

Error Code	Description	Platform
NOT_SUPPORTED_ERROR	Google Play Services not available or outdated	Android only
NO_ACTIVITY_ERROR	No Android activity context available	Android only

Notes

• Always check PASSWORD_SUPPORTED before calling this method
• The password cannot be a previously stored credential retrieved via getPassword
• Only call this method after successful backend authentication
• Available on both Android (API 24+) and iOS (12+)
• The credential will be synced via iCloud Keychain (iOS) or Google Password Manager (Android)

Example Usage (TypeScript)

import { passwordSignIn, PASSWORD_SUPPORTED } from 'react-native-oauth-essentials';

async function signInWithPassword(username: string, password: string): Promise<void> {
  if (!PASSWORD_SUPPORTED) {
    console.log('Password sign-in is not supported on this platform.');
    return;
  }

  try {
    // First authenticate with your backend
    const authSuccess = await authenticateWithBackend(username, password);

    if (!authSuccess) {
      console.log('Invalid credentials');
      return;
    }

    // Save credentials to credential manager for future auto sign-in
    const saved = await passwordSignIn(username, password);

    if (saved) {
      console.log('Credentials saved successfully - will auto sign-in next time');
    } else {
      console.log('Failed to save credentials - will need to sign in manually next time');
    }
  } catch (error) {
    console.error('Password sign-in error:', error);
  }
}

Best Practices

1. Always try getPassword() first - Check for stored credentials before showing login UI
2. Only save after backend validation - Don't save credentials until your backend confirms they're valid
3. Handle the CANCELLED case gracefully - getPassword() resolving CANCELLED is normal, not an error
4. Sync benefits - Saved credentials work across all user's devices via iCloud/Google sync
5. Security - Credentials are encrypted and stored securely by the OS
6. Combine with biometrics - Consider adding biometric authentication for extra security

Recommended Flow

async function handleAuth() {
  // 1. Try to get saved credentials first
  const saved = await getPassword();

  if (saved.type === CredentialsType.PASSWORD) {
    // Auto sign-in with saved credentials
    await authenticateWithBackend(saved.data.username, saved.data.password);
    return;
  }

  // 2. No saved credentials, show login UI
  const { username, password } = await showLoginUI();

  // 3. Authenticate with backend
  const success = await authenticateWithBackend(username, password);

  if (success) {
    // 4. Save credentials for next time
    await passwordSignIn(username, password);
  }
}

Platform-Specific Details

iOS (12+)

• Stored in iOS Keychain (highly secure)
• Synced via iCloud Keychain to all user's Apple devices
• Supports AutoFill in Safari and WKWebView
• Integrated with Face ID / Touch ID prompts

Android (7.0+ / API 24+)

• Uses Credential Manager API
• Synced via Google Password Manager to all user's devices with same Google account
• Supports AutoFill framework in apps and browsers
• Can prompt for device authentication (PIN/fingerprint/face)