Build-your-own? A smart-home-controller is a physical device. You buy it, you provide power and connect ethernet and configure wifi. Now, either the controller

Build-your-own? A smart-home-controller is a physical device. You buy it, you provide power and connect ethernet and configure wifi. Now, either the controller relies on the cloud or it doesn't. If it is completely reliant on the cloud you will have to muck about with registering, if it is completely self-hosted you don't. Simple as that.