⏰ True Time Provider for Flutter #

A secure and reliable time provider for Flutter apps. Fetches accurate time from NTP servers, with Firebase and device time as fallbacks.

Screenshots #

Table of Contents #

• Features
• Installation
• Usage
• How It Works
• Example Use Cases
• Configuration
• Limitations
• Roadmap
• License

✨ Features #

• ✅ Provides accurate, tamper-resistant current time
• ✅ Built-in Singleton pattern (global instance)
• ✅ Multi-source fallback (NTP → Firebase → Device)
• ✅ Handles network failures gracefully
• ✅ Supports IPv4 & IPv6
• ✅ Configurable NTP host, port, and timeout

Installation #

Add this to your pubspec.yaml:

dependencies:
  true_time_provider: latest_version

Install it with:

flutter pub get

Usage #

1. Initialize at app startup #

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  // Initialize Firebase fallback
  TrueTimeProvider.instance.init(
    options: DefaultFirebaseOptions.currentPlatform,
  );

  runApp(MyApp());
}

2. Fetch secure time #

final DateTime safeNow = await TrueTimeProvider.instance.now();
print("Secure current time: $safeNow");

🛠 How It Works #

Fallback Flow #

try NTP server
   │
   ├── success → return ntpTime
   │
   └── fail → try Firebase
               │
               ├── success → return fireSTime
               │
               └── fail → return DateTime.now() (device)

Class Overview #

• TrueTimeProvider → Singleton entry point
• NtpServerProvider → Fetches time via UDP NTP
• FirebaseCloudProvider → Fetches server time from Firestore
• Device Time → Final fallback

⚡ Example Use Cases #

• Banking / Payment apps
• Event logging / Audit trails
• Subscription & licensing apps
• Distributed systems

🔧 Configuration #

Override NTP lookup options:

final time = await TrueTimeProvider.instance.now(
  ntpFetchDuration: Duration(seconds: 20),
  ntoLookUpAddress: "pool.ntp.org",
  ntpLookupPort: 123,
);

Limitations #

• NTP requires UDP port 123 (may be blocked in some networks)
• Firebase fallback requires internet access
• Falls back to device time if both fail
• Currently only one NTP request per call (no retries)

Roadmap #

• ❌ Retry mechanism with exponential backoff
• ❌ Cache last known good offset
• ❌ Expose NTP sync statistics (delay, jitter)
• ❌ Add tests with mock NTP responses

License #

This project is licensed under the MIT License.