Events

Use app.on() to listen to broker lifecycle events. With @mqttkit/aedes, events come from Aedes.

Supported Events

import type { MqttEventName } from '@mqttkit/core'

const eventNames: MqttEventName[] = [
  'client',
  'clientReady',
  'clientDisconnect',
  'keepaliveTimeout',
  'clientError',
  'connectionError',
  'connackSent',
  'ping',
  'publish',
  'ack',
  'subscribe',
  'unsubscribe',
]

Usage

const app = new MqttApp()
  .use(aedes({ tcp: { port: 1883 }, ws: { port: 8888, path: '/mqtt' } }))
  .use(router().topic('devices/:uid/events', { onMessage }))

app.on('client', (event) => {
  console.log('client connected', event.clientId)
})

app.on('publish', (event) => {
  console.log('publish', event.clientId, event.topic)
})

app.on('ack', (event) => {
  console.log('ack', event.clientId, event.topic)
})

await app.listen()

ACK Semantics

mqttkit does not implement custom ack and does not send JSON ack messages to WebSocket clients. The ack event comes from the Aedes MQTT packet lifecycle, and its exact timing follows the broker and MQTT protocol implementation.

If your application needs an application-level receipt, publish one explicitly from the handler:

router().topic('devices/:uid/events', {
  async onMessage(ctx) {
    await ctx.publish(`server/${ctx.params.uid}/acks`, {
      topic: ctx.topic,
      accepted: true,
    })
  },
})