I'm sure the Cool Automation is the easier path, but about six months ago I created C# JSON I/F module for 4x Daiken Emura system using their latest APIs and WiFi modules.? I made the module look like a TSTAT to make integration with an older UI that had radiant floor heat easier.? ? System has been solid.? Daiken's APIs are pretty well documented.? Even so, I probably spent more time than I wanted on this but in the end was happy with result.