followben / NextMQTT

A modern Swift MQTT client

NextMQTT

NextMQTT is a modern MQTT 5.0 client for iOS and watchOS.

It currently includes basic functionality including subscribe/ unsubscribe and publish/ receive with "at most once" (QoS 0) delivery.

Although the project is actively maintained, it is not yet production-ready and contributions are welcome.

Use

Closures may be called on a background thread. Always dispatch to main before updating UI from a NextMQTTT closure.

Create

mqtt = MQTT(host: "127.0.0.1", port: 1883)
// or
mqtt = MQTT(host: "my.mqttserver.com", port: 1883, username: "myuser", password: "mypassword", options: [
    .secureConnection: true,
    .pingInterval: 10,
    .clientId: "myclientid",
    .maxBuffer: 16384
])

Connect

mqtt.connect { result in
    switch result {
    case .success():
        print("connected")
    case .failure(let error):
        print(error.description)
    }
}

Subscribe

let filter = "mytopics/#"
mqtt.subscribe(to: filter) { result in
    switch result {
    case .success():
        print("subscribed")
    case .failure(let error):
        print(error.description)
    }
}

Unsubscribe

let filter = "mytopics/#"
mqtt.unSubscribe(from: filter) { result in
    switch result {
    case .success():
        print("unsubscribed")
    case .failure(let error):
        print(error.description)
    }
}

Publish

let jsonMessage = ["key" : "value"]
let encodedMessage = try! JSONEncoder().encode(json)
let topic = "mytopics/atopic"
mqtt.publish(to: topic, data: encodedMessage)

Receive

mqtt.onReceive = { topic, encodedMessage in
    print("received publish from \(topic)")
    if let data = encodedMessage, let message = try? JSONDecoder().decode(Message.self, from: data) {
        print(message)
    }
}

Monitor

mqtt.onConnectionState = { state in
    print("new connection state is \(state)")
}

Install

In your Xcode project, select File > Swift Packages > Add Package Dependency... and add https://github.com/followben/NextMQTT. For the latest stable changes, select the master branch.

NextMQTT has been tested on watchOS 6 and iOS 13. In theory NextMQTT will also work on macOS 12 and tvOS but this hasn't been verified.

Contribute

PRs are welcome. For major changes, open an issue first to discuss what you would like to change.

Please ensure tests pass and are up-to-date.

Roadmap

Planned features include:

• Support for QoS 1 and 2 incl. session state
• Properties, incl. User Properties
• Publish with retain
• Will Messages
• Extended authentication flows

There is currently no plan to support MQTT 3.1, Websockets or Shared Subscriptions.

License

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