MQTT server that supports MQTT 3.1 or 3.1.1 and can connect to them over TCP, TLS, or a Websocket connection using `tcp://`, `tls://`, or `ws://` respectively as the scheme for the broker url. See the [Go Client](http://www.eclipse.org/paho/clients/golang/) documentation for more information.

Note that, you can add as many MQTT server endpoint configurations as needed by providing an identifier (like "1" in the example above) for the MQTT instance and an object of per-server configuration...