MQTT Server #

A lightweight, efficient MQTT broker implementation in pure Dart. This package provides a full-featured MQTT server that can be embedded in your Dart applications or run as a standalone broker.

Features #

• MQTT 3.1.1 Protocol Support: Implements the MQTT 3.1.1 protocol specification
• QoS Levels: Supports QoS 0, 1, and 2 message delivery
• Session Persistence: Optional persistent sessions across client reconnects
• Authentication: Built-in username/password authentication system
• SSL/TLS Support: Secure connections with SSL/TLS
• Will Messages: Support for last will and testament messages
• Retained Messages: Store and forward retained messages to new subscribers
• Topic Wildcards: Support for + and # wildcards in topic subscriptions
• Clean Architecture: Modular design with clear separation of concerns

Getting Started #

Installation #

Add the package to your pubspec.yaml:

dependencies:
  mqtt_server: ^1.0.0

Then run:

dart pub get

Prerequisites #

• Dart SDK 3.0.0 or higher

Usage #

Basic Broker Setup #

import 'package:mqtt_server/mqtt_server.dart';

Future<void> main() async {
  // Create a broker with default configuration
  final broker = MqttBroker();
  
  // Start the broker
  await broker.start();
  
  print('MQTT broker running on port 1883');
}

Custom Configuration #

import 'package:mqtt_server/mqtt_server.dart';

Future<void> main() async {
  // Create a broker with custom configuration
  final config = MqttBrokerConfig(
    port: 8883,
    useSSL: true,
    sslCertPath: 'path/to/certificate.pem',
    sslKeyPath: 'path/to/key.pem',
    allowAnonymous: false,
    enablePersistence: true,
    persistencePath: 'mqtt_data/sessions.json',
    sessionExpiryInterval: Duration(days: 1),
  );
  
  final broker = MqttBroker(config);
  
  // Add user credentials
  broker.addCredentials('username', 'password');
  
  // Start the broker
  await broker.start();
  
  print('Secure MQTT broker running on port 8883');
}

Advanced Usage #

Session Persistence #

The broker can automatically persist sessions to disk and restore them on restart:

final config = MqttBrokerConfig(
  enablePersistence: true,
  persistencePath: 'data/sessions.json',
);

final broker = MqttBroker(config);

// Sessions will be saved periodically and on clean shutdown
await broker.start();

// To manually trigger session persistence
await broker.savePersistentSessions();

API Reference #

For detailed API documentation, see the API reference.

Examples #

Check the /example directory for more comprehensive examples:

• Basic broker setup
• Secure broker with SSL/TLS
• Authentication examples
• Custom packet handling

Contributing #

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License #

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments #

• MQTT Protocol Specification: MQTT.org
• Inspired by other MQTT implementations like Mosquitto and HiveMQ