Feasibility check: REST as input, MQTT as status updates


I am trying to integrate my home domotics (closed source switch, dimmer, shutter). I can access all the outputs via REST and the status update is for now via a REST pull request.
There is in the closed system also an event listener with closed source dll in windows. I can receive these events, parse/translate them and log them (eg button x pushed, shutter y goes up, …). I want now to integrate these events in HASS as status updates. I would like to link both systems with MQTT as PUSH. This will make the system constantly updated with no overhead, eg when a real button on the wall is pushed.

So here my questions:

  • in my platform code, there is REST to access the equipment. Can I integrate the status update procedure with MQTT-parser?
  • how do i configure the configuration yaml to identify the message for that specific output? Or is this inside the generic MQTT section?
  • I think that I read an article that the latest HASS has now a MQTT server built inside but I can not find this info any more. Do we still need a seperate MQTT server?

I use this integration project to migrate my primary programming language from VB.net to Python, so my code is for now home-made-noobie-spaghetti. I will optimise and the give this as a new platform to the community. It is for a local domotics system from Belgium.