The MQTT integration needs you to run an MQTT broker for Home Assistant to connect to.
The most private option is running your own MQTT broker.
The recommended setup method is to use the Mosquitto MQTT broker add-on.
Neither ActiveMQ MQTT broker nor the RabbitMQ MQTT Plugin are supported, use a known working broker like Mosquitto instead. There are at least two issues with the ActiveMQ MQTT broker which break MQTT message retention. There is an issue with the RabbitMQ MQTT Plugin which breaks MQTT message retention.
The Mosquitto project runs a public broker. This is the easiest to set up, but there is no privacy as all messages are public. Use this only for testing purposes and not for real tracking of your devices or controlling your home. To use the public mosquitto broker, confiure the MQTT integration to connect to broker
test.mosquitto.org on port 1183 or 8883.
If you experience an error message like
Failed to connect due to exception: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed, then add
certificate: auto to your broker configuration and restart Home Assistant.
MQTT broker settings are configured when the MQTT integration is first setup, and can be changed if needed. To change the settings, click on “Configure” in the integration page in the UI, then “Re-configure MQTT”.
Some broker configuration options can’t be set via the user interface, but require changes of your
Additional SSL certificate options are documented here.
The client ID that Home Assistant will use. Has to be unique on the server. Default is a randomly generated one.
The time in seconds between sending keep alive messages for this client. Default is 60.
Protocol to use: 3.1 or 3.1.1. By default it connects with 3.1.1 and falls back to 3.1 if server does not support 3.1.1.
If you are running a Mosquitto instance on a different server with proper SSL encryption using a service like Let’s Encrypt you may have to set the certificate to the operating systems own
.crt certificates file. In the instance of Ubuntu this would be