NTP Dart

NTP Dart is a lightweight and cross-platform Dart/Flutter plugin that keeps your app’s clock in sync using NTP servers (on mobile/desktop) or HTTP time endpoints (on web). It provides accurate UTC DateTime values for authentication, logging, and time-sensitive logic.

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📱 Supported Platforms

Android	iOS	macOS	Web	Linux	Windows
✔️	✔️	✔️	✔️	✔️	✔️

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🔍 Overview

ntp_dart ensures your app maintains accurate UTC time across platforms.

• On mobile/desktop, it uses NTP protocol (UDP).
• On web, it uses HTTP to fetch time from a JSON endpoint like https://worldtimeapi.org/api/timezone/etc/utc.

This is crucial for:

• Secure token verification
• Time-based triggers
• Audit logs
• UI clocks and timers

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⚙️ Installation

Add to your pubspec.yaml:

dependencies:
  ntp_dart: ^1.0.0

Then install:

flutter pub get

Import it:

import 'package:ntp_dart/ntp_base.dart';
import 'package:ntp_dart/accurate_time.dart';

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🔧 Usage

📡 Direct Fetch (No Caching)

Fetch fresh UTC time from the server every time:

final nowUtc = await NtpClient().now();

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🧠 Cached Fetch with Sync Interval

Use AccurateTime.now() to avoid redundant requests and auto-sync periodically (default: every 60 minutes):

final nowUtc = await AccurateTime.now();

You can customize the interval:

AccurateTime.setSyncInterval(Duration(minutes: 30));

Need a synchronous value (e.g., for UI updates)? Use AccurateTime.nowSync(). It returns the cached UTC time immediately and triggers a background sync if the cache is missing or stale:

final nowUtc = AccurateTime.nowSync();

On web, AccurateTime fetches time from a JSON endpoint (default: https://worldtimeapi.org/...) and caches it for the given interval.

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📘 API Reference

Method	Description
NtpClient({ String server = 'pool.ntp.org', int port = 123, int timeout = 5 })	Constructor. Creates a new NTP client (non-Web only).
Future<DateTime> NtpClient().now()	Fetches fresh UTC time from the specified NTP server.
Future<DateTime> AccurateTime.now()	Returns cached UTC time or resynchronizes if the sync interval has expired.
DateTime AccurateTime.nowSync()	Returns cached UTC time synchronously and triggers a background sync if needed.
void AccurateTime.setSyncInterval(Duration duration)	Sets how often a new time sync should occur. Default: 60 minutes.

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💡 Common Use Cases

• ✅ Token validation using accurate UTC for Firebase JWTs — see firebase_verify_token_dart
• 🕒 Cross-platform logging with consistent time
• 🔔 Scheduled actions (notifications, tasks, resets)
• 🔄 Time-coordinated data sync
• 🧭 UI clocks that stay accurate over time

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🤝 Contributing

Have feedback or a fix?
Open an issue or submit a pull request.

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📃 License

MIT License. See LICENSE.