📱 device_id_manager #

A cross-platform Flutter plugin that generates and persists unique device IDs — even after reinstalling the app. Built for apps that need a reliable, persistent device identifier with zero permissions.

✨ Features #

• 🔒 Persistent across app reinstalls on both iOS and Android
• 🏷️ Per-app unique IDs on Android (different apps on the same device get different IDs)
• 🚫 No permissions required
• 👤 Identified user support via logIn() / logOut()
• ⚡ Synchronous access after initialization — no await needed for getters
• 🛡️ Secure storage — iOS Keychain (AES-256), Android MediaDrm (hardware-backed)
• 💥 Fail-safe — throws StateError if accessed before initialize()

🧠 How It Works #

🍏 iOS #

1. Checks Keychain for an existing ID (user_device_id key)
2. If not found, generates a UUID v4 and stores it in Keychain
3. Keychain data persists across app reinstalls

🤖 Android #

1. Gets hardware device ID via MediaDrm API
2. Combines with app package name: "$mediaDrmId:$packageName"
3. Applies SHA-256 hash → per-app unique ID
4. Falls back to UUID v4 if MediaDrm is unavailable (rooted devices, emulators, custom ROMs)

📊 Platform Comparison #

📦 Installation #

Add to your pubspec.yaml:

dependencies:
  device_id_manager: ^1.0.0

Then run:

flutter pub get

🍏 iOS Setup #

Add the following to your ios/Runner/Info.plist if not already present (required by flutter_secure_storage):

<key>NSFaceIDUsageDescription</key>
<string>We use Face ID to protect your data</string>

🤖 Android Setup #

Minimum SDK 18 is required. In android/app/build.gradle:

android {
    defaultConfig {
        minSdkVersion 18
    }
}

🛠️ Usage #

Basic #

import 'package:device_id_manager/device_id_manager.dart';

// Initialize once at app startup
await DeviceIdManager.initialize();

// Access device ID (synchronous, non-null)
String id = DeviceIdManager.deviceId;
print('Device ID: $id');

👤 Identified Users (Login / Logout) #

// Log in with a custom user ID
await DeviceIdManager.logIn('user_12345');

print(DeviceIdManager.isAnonymous);  // false
print(DeviceIdManager.appUserId);    // user_12345
print(DeviceIdManager.customUserId); // user_12345

// Log out — reverts to anonymous device ID
await DeviceIdManager.logOut();

print(DeviceIdManager.isAnonymous);  // true
print(DeviceIdManager.appUserId);    // null
print(DeviceIdManager.customUserId); // <device_id>

🔇 Logging #

// Disable logs
DeviceIdLogger.setEnabled(false);

// Enable logs (default)
DeviceIdLogger.setEnabled(true);

📚 API Reference #

DeviceIdManager #

⚠️ Important: Accessing any getter before initialize() throws a StateError.

🚧 Limitations #

• MediaDrm only available on Android API ≥ 18
• On some custom or rooted ROMs, MediaDrm may be unreliable
• Factory reset will remove the iOS Keychain ID
• On iOS, Keychain-based ID may reset if iCloud Keychain is disabled or device is restored without backup

🔍 Example #

Clone the repository and run the example app:

cd example
flutter run

📄 License #

MIT License. © 2025