@mysetup/mqtt-client

A utility for managing MQTT connections, subscriptions, publishing, and client caching, built on top of the mqtt library.

Features

• Connect to MQTT brokers with custom configuration
• Subscribe and unsubscribe to topics
• Publish messages to topics
• Handle connection events (connect, error, reconnect, close, offline)
• Cache and reuse MQTT clients by clientId
• Custom message callbacks
• Integration with a logger and cache system

Installation

npm install @mysetup/mqtt-client

Usage

import { mqttCreateConnection, mqttSub, mqttPublish, mqttDisconnect } from "@mysetup/mqtt-client";

const clientId = "myClientId";
const config = {
    protocol: "mqtt",
    host: "localhost",
    port: 1883,
    path: "",
    username: "user",
    password: "pass",
};

const topicList = ["my/topic"];

mqttCreateConnection({
    clientId,
    config,
    topicList,
    messageCallback: (topic, message) => {
        console.log(`Received on ${topic}: ${message}`);
    },
    environment: "development", // Optional: enables verbose logging
});

// Subscribe to topics
mqttSub(topicList, clientId, (topic, message) => {
    console.log(`Received: ${message} on ${topic}`);
});

// Publish a message
mqttPublish("my/topic", { hello: "world" }, clientId);

// Disconnect
mqttDisconnect({ clientId, config, topicList }, false);

Functions

• mqttCreateConnection(props: ConnectionProps): MqttClient Creates or retrieves a cached MQTT client and connects to the broker.

• mqttSub(topicList, clientId, messageCallback?, environment?) Subscribes to the given topics for the specified client.

• mqttUnSub(topicList, clientId, environment?) Unsubscribes from the given topics for the specified client.

• mqttPublish(topic, message, clientId, environment?) Publishes a message to a topic.

• mqttDisconnect(props, reinit, environment?) Disconnects the client and optionally reinitializes the connection.

• getMqttClient(clientId) Retrieves the cached MQTT client by ID.

License

MIT