@priemskiyyy/simulcast-mqtt

MQTT adapter for simulcast, built on mqtt.js. Requires mqtt 5.

Installation

pnpm add @priemskiyyy/simulcast @priemskiyyy/simulcast-mqtt mqtt

Create a client

import { RealtimeClient } from "@priemskiyyy/simulcast";
import { mqtt } from "@priemskiyyy/simulcast-mqtt";

const realtime = new RealtimeClient({
  adapter: mqtt({
    url: "wss://broker.example.com/mqtt",
    options: { username, password },
    getSubscribeOptions: () => ({ qos: 1 }),
  }),
});

Behavior

A channel is a topic filter, so rooms/+ and rooms/# work and each publication is routed to every filter its topic matches. data is the raw payload Buffer, and native is the publish packet with its QoS, retain flag, and properties. A granted subscription reports subscribed; a rejected one (QoS 128) reports the grant as an error and unsubscribed. Because mqtt.js resubscribes silently after a reconnect, channels report subscribing while the client is offline and subscribed once it reconnects. The connection reports connecting after every close unless reconnectPeriod is 0.

Root wildcard filters (# or +) exclude topics starting with $; subscribe explicitly to $SYS/# for system topics. With reconnectPeriod: 0, a closed connection reports disconnected and its granted subscriptions report unsubscribed.

Messages can arrive before the subscription acknowledgement. After a subscription fails, its handler stops receiving publications, including messages received through an overlapping accepted filter. A connection reconnect alone does not grant a rejected subscription; recreating the subscription starts a new attempt.

Guides

• Installation and framework setup
• Adapter configuration and state mappings
• Connection sessions
• Testing consumers without a provider

License

MIT