Device for reading room temperature and changing setpoint

Is there anything with local API that can be used to read current room temperature and also allow me to change and read temperature setpoint? I will have more than one heat source and want to apply certain logic when to use each of them. For example, if it is really cold outside, I would open TRV valve (which turns on pellet boiler) instead of using heat pump. Now I have to control them both manually and separately.
So basically I need something similar to Nest or Ecobee, but without the need for them to control heating or cooling directly. I just need some API to read current temperature and setpoint. It can be WiFi, Zigbee, Z-Wave as long as I can communicate with it somehow.

Honeywell T6 Pro has a Z-Wave option. There is also a WiFi device, but I could not find an information if it has local API. Might be cloud only and I’m not sure if it will be available for Europe. Any other similar devices?