mqtt_client

mqtt_client

A server and browser based MQTT client for Dart.

The client is an MQTT v3(3.1 and 3.1.1) implementation(an equivalent MQTT v5 client can be found here) supporting subscription/publishing at all QOS levels, keep alive and synchronous connection. The client is designed to take as much MQTT protocol work off the user as possible, connection protocol is handled automatically as are the message exchanges needed to support the different QOS levels and the keep alive mechanism. This allows the user to concentrate on publishing/subscribing and not the details of MQTT itself.

Examples of usage can be found in the examples directory. An example is also provided showing how to use the client to connect to the mqtt-bridge of Google's IoT-Core suite. This demonstrates how to use secure connections and switch MQTT protocols. The test directory also contains standalone runnable scripts demonstrating subscription, publishing and topic filtering.

The server client supports both normal and secure TCP connections and secure(wss) and non-secure(ws) websocket connections. The browser client supports only secure(wss) and non-secure(ws) websocket connections.

The client has been used successfully with the MQTT brokers from several of the major cloud providers IOT/MQTT platforms, including :-

• Google IOT Core
• Amazon AWS
• Microsoft Azure
• IBM

It has also been used with a range of both publicly available brokers such as Mosquitto and proprietary ones. An example using the adafruit MQTT broker for flutter can be found here.

The code is originally a port from the C# nMQTT client library to Dart.

Please read the changelog for details related to specific versions.

Installation

If you are using the client in a flutter environment on Android or iOS devices then the following device permission settings are necessary.

iOS

Add the following keys to your Info.plist file, located in ios/Runner/Info.plist:

<key>NSLocalNetworkUsageDescription</key>
<string>Looking for local tcp Bonjour service</string>
<key>NSBonjourServices</key>
<array>
  <string>mqtt.tcp</string>
</array>

Android

Add the following Android permissions to the AndroidManifest.xml file, located in android/app/src/main/AndroidManifest.xml:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

License