flutter_ntp 0.1.0

A small, fast NTP (Network Time Protocol) client for Flutter and Dart with built-in offset caching.

flutter_ntp

A small, fast NTP (Network Time Protocol) client for Flutter and Dart.

• Pure Dart, no platform channels — works on Android, iOS, macOS, Windows, Linux.
• Sync once, read forever: the offset between device and server is cached, so subsequent calls are instant.
• 40+ public NTP servers built in, or pass any host name.
• Typed NtpException, configurable timeout, optional fallback to device clock.

Install

dependencies:
  flutter_ntp: ^0.1.0

flutter pub get

Usage

import 'package:flutter_ntp/flutter_ntp.dart';

Quick start

// One time, somewhere early in your app:
await FlutterNTP.sync();

// Anywhere else — instant, no network:
final accurateNow = FlutterNTP.nowSync();
print('NTP time : $accurateNow');
print('Offset   : ${FlutterNTP.offset}');

One-shot

final ntpNow = await FlutterNTP.now();         // re-uses the cache when fresh
final ntpNow = await FlutterNTP.now(forceRefresh: true); // always re-sync

Pick a server / set a timeout

await FlutterNTP.sync(
  server: NtpServer.cloudflare,
  timeout: const Duration(seconds: 3),
);

// Or a custom host:
await FlutterNTP.sync(lookUpAddress: 'my-internal-ntp.example.com');

Error handling

FlutterNTP.now() falls back to DateTime.now() by default if the network call fails — useful in offline scenarios. Pass allowFallback: false to make failures explicit:

try {
  final t = await FlutterNTP.now(allowFallback: false);
} on NtpException catch (e) {
  // handle network / DNS / timeout
}

Inspect / reset the cache

FlutterNTP.offset;          // Duration? — last known server-device offset
FlutterNTP.lastSyncAt;      // DateTime? — when sync last succeeded
FlutterNTP.lastSyncServer;  // String?   — host name of last sync
FlutterNTP.clearCache();    // forget everything

Available servers

google · cloudflare · facebook · microsoft · apple · nist · pool · usno · isc
timeNl · chrony · hetzner · hetzner2 · ntpSe · qix · mskIx · ripe · ispClockIsc
natMorris · eduUtcnist · ntpstm · netGps · ptb · plNtp · fuBerlin · surfnet
asynchronos · czNtp · roNtp · lysator · caTime · mxCronos · esHora · itInrim
beOma · huAtomki · eusI2t · chNeel · cnNeu · jpNict · brUfrj · clShoa · intEsa

Platform support

Platform	Supported
Android / iOS	✅
macOS / Windows / Linux	✅
Web	❌ (no UDP)

FlutterNTP.isSupported is false on the web.

Support

If you find this package useful, consider supporting the author: