MQTT Publish service

The MQTT integration will register the service mqtt.publish which allows publishing messages to MQTT topics. There are two ways of specifying your payload. You can either use payload to hard-code a payload or use payload_template to specify a template that will be rendered to generate the payload.

Service mqtt.publish

Service data attribute Optional Description
topic no Topic to publish payload to.
payload yes Payload to publish.
payload_template yes Template to render as payload value. Ignored if payload given.
qos yes Quality of Service to use.
retain yes If message should have the retain flag set. (default: false)
You need to include either payload or payload_template, but not both.
topic: home-assistant/light/1/command
payload: on
topic: home-assistant/light/1/state
payload_template: {{ states('device_tracker.paulus') }}

payload must be a string. If you want to send JSON then you need to format/escape it properly. Like:

topic: home-assistant/light/1/state
payload: "{\"Status\":\"off\", \"Data\":\"something\"}"

Example of how to use qos and retain:

topic: home-assistant/light/1/command
payload: on
qos: 2
retain: true