Apple Sign In Plugin

A comprehensive, backend-ready Flutter package for integrating Apple Sign-In. It provides secure authentication, automatic token management, and returns a complete result object (including JWT, refresh token, access token) essential for backend verification.

Features

• 🔐 Secure Authentication: Handles the complete Apple Sign-In flow.
• 📦 Backend Ready: Returns idToken, accessToken, and refreshToken for server-side validation.
• 🔄 Token Management: Automatic handling of refresh tokens and revocations.
• 👤 User Data: Retrieves name, email, and stable user ID.
• 📱 Cross-Platform: Supports iOS, MacOS, Android, and Web (via sign_in_with_apple).

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  apple_sign_in_plugin: ^1.2.1

Setup & Prerequisites

Before using this plugin, ensure you have the following from your Apple Developer Account:

1. Service ID / Bundle ID: The identifier for your app.
2. Team ID: Your Apple Team ID.
3. Key ID: The ID of the private key.
4. Private Key File (.p8): Download this from Apple and rename it to apple_private_key.pem.

Asset Configuration

Add your private key file to your Flutter assets in pubspec.yaml:

flutter:
  assets:
    - assets/keys/apple_private_key.pem

Usage

1. Initialization

Initialize the plugin with your credentials. This is usually done in main.dart or before the first sign-in attempt.

await AppleSignInPlugin.initialize(
    pemKeyPath: 'assets/keys/apple_private_key.pem',
    keyId: 'YOUR_KEY_ID',
    teamId: 'YOUR_TEAM_ID',
    bundleId: 'YOUR_BUNDLE_ID', // e.g., com.example.app
);

2. Sign In

Call signInWithApple() to start the flow. It returns an AppleSignInResult object containing everything you need.

try {
  final AppleSignInResult? result = await AppleSignInPlugin.signInWithApple();

  if (result != null) {
      print("Sign In Successful!");
      
      // Use these for backend verification:
      print("ID Token (JWT): ${result.idToken}"); 
      print("Access Token: ${result.accessToken}");
      print("Refresh Token: ${result.refreshToken}");
      
      // User Profile:
      print("Email: ${result.email}");
      print("User ID: ${result.userIdentifier}");
      print("Name: ${result.givenName} ${result.familyName}");
  } else {
      print("Sign In Cancelled");
  }
} catch (e) {
  print("Sign In Failed: $e");
}

3. Sign Out

Securely sign out and revoke tokens.

await AppleSignInPlugin.signOut();

📦 What do you get back? (AppleSignInResult)

The plugin returns an AppleSignInResult object with everything you need. Here is what each field means:

Field	Description	Why do I need it?
idToken	A JSON Web Token (JWT) that proves the user's identity.	Crucial for Backend: Send this to your server to verify the user is real.
accessToken	A short-lived token for Apple API calls.	Used if your server needs to talk to Apple APIs.
refreshToken	A long-lived token.	Used to get a new accessToken when the old one expires.
authorizationCode	A one-time code.	The plugin uses this to get the tokens above. You rarely need this manually.
userIdentifier	A unique User ID (e.g., 000xxx...).	Database Key: Use this to find/create the user in your database.
email	User's email address.	To contact the user.
givenName	First Name.	First Login Only: Save this immediately! Apple only sends it once.
familyName	Last Name.	First Login Only: Save this immediately!

Important Notes

• Simulator Issues: Apple Sign-In may not work correctly on iOS Simulators. Test on a real device.
• Android/Web: This plugin wraps sign_in_with_apple logic for broad compatibility, but ensure your Apple Service ID is configured for web callbacks if using on non-Apple platforms.

License

MIT License. See LICENSE for details.