This project provides the following two different components :

• server : it's able to handle connections, communication and messages exchange with remote MQTT clients. Its API provides a bunch of events related to raw protocol messages received by clients and exposes some functionalities in order to send messages to them. It's not a fully featured MQTT broker but can be used for building something like that or for protocol translation (MQTT <--> ?).
• client : it's an MQTT client which is compliant with the 3.1.1 spec. Its API provides a bunch of methods for connecting/disconnecting to a broker, publishing messages (with all three different levels of QoS) and subscribing to topics.

See the in-source docs for more details:

• Java.
• JavaScript.
• Ruby.
• Groovy.
• Kotlin.

Some examples are available for getting started with the server under the vertx-examples project.

Note: This module has Tech Preview status, this means the API can change between versions.