Quarkus HiveMQ Client

This extension lets you use the HiveMQ MQTT Client inside a Quarkus application, in both JVM and native mode.

Together with the SmallRye Reactive Messaging MQTT extension it contributes a new connector, smallrye-mqtt-hivemq, that uses the HiveMQ Client under the hood instead of the default Vert.x MQTT client. You interact with it through the standard MicroProfile Reactive Messaging API (@Incoming / @Outgoing), so switching connector requires no code changes.

Why use it

Compared to the stock SmallRye MQTT connector, this extension adds:

A battle-tested MQTT client that does not depend on the Vert.x MQTT client
TLS, mutual TLS and custom CA / self-signed certificate support
Backpressure integrated with MQTT QoS
Native mode support
Dev Services — a broker is started automatically for dev and test
Automatic, configurable reconnection and message redelivery
A real health check against a configurable topic (defaults to $SYS/broker/uptime), wired into the Quarkus SmallRye Health report
Everything else offered by the underlying client — see the HiveMQ MQTT Client documentation

How it works

@Outgoing / @Incoming  ─▶  SmallRye Reactive Messaging  ─▶  smallrye-mqtt-hivemq connector  ─▶  HiveMQ MQTT Client  ─▶  MQTT broker

You declare channels in application.properties, bind them to the smallrye-mqtt-hivemq connector, and produce or consume messages with plain Reactive Messaging beans. The connector supports MQTT 3.1.1.

What’s next

Installation — add the extension to your project
Usage — produce and consume messages
Security & TLS — authentication, TLS and mutual TLS
Configuration Reference — every connector option