MQTT Event Bus Publication [3.2.0;3.4.9]


Note, in the first half of 2023, this rule template will be rewritten to only support JS Scripting.

This is one of three rules used to create an MQTT Even Bus. The other rules are MQTT Online Status and MQTT Event Bus Subscribe.This rule is responsible for parsing the messages received on an event bus and commanding or updating Items as necessary. See MQTT 2.5+ Event Bus for details on how to set up and configure an MQTT Even Bus.

Warning, to avoid infinite loops, do not publish and subscribe the same event on the same Items.

openHAB instance Publishes Subscribes
Linked to device updates commands
Remote commands updates

The rule has the following parameters:

Parameter Purpose
MQTT Broker Thing Select the MQTT Broker Thing to publish to.
openHAB instance name The name of this openHAB instance, will be used as the root of the topic events are published to.
Command Group The Group whose member’s commands are published to the event bus.
Update Group The Group who memember’s updates are published to the event bus.

Language: Nashorn JavaScript


  • MQTT Binding installed
  • MQTT Broker Thing created and configured
  • A Group containing those Items who should have their commands published.
  • A Group containing those Items who should have their updates published.
  • In OH 4 the Nashorn add-on needs to be separately installed or change the script type to application/javascript;version=ECMAScript-2021.


Version 0.3

  • adjusted for breaking change, will no longer work for versions of OH prior to December 15th

Version 0.2

  • Made compatible with Nashorn and JSScripting
    Note: will remove support for Nashorn sometime after OH 3.2 release.

Version 0.1

  • initial release