I use an ecobee termostat with Wifi and three extra sensores places around my home. Home Assistant already has an add-on for it, add the thermostat card and it goes to work. Set whatever automations you want.

You might reach out to the open source initiative if your app is open source. They have lawyers, and may be willing to provide guidance at the very least. I’m just guessing, and don’t work for the OSI, nor know for sure whether they will or wont help in any way. Just another place to look. At the very least they may be able to suggest attorneys who might be willing to help out.