Home Assistant is the leader here. One of the largest projects on GitHub with a “local-first” philosophy. They have a cloud service for exposing your instance

Home Assistant is the leader here. One of the largest projects on GitHub with a “local-first” philosophy. They have a cloud service for exposing your instance but you don’t have to use it. I’ve been using it for years and it’s matured quite a bit recently. Combine with Zwave of ZigBee devices and the only thing you need internet for is voice assistant if you want it (Totally not required)