To expand a bit, search "home assistant" or "hubitat."
Both are great, but home assistant is open source, and has the bigger community who support more devices. It is a bit more DIY than hubitat, but they have released their own hardware to go with the software, so its getting easier all the time. You can also run it on your own hardware if youre handy.
Hubitats advantages are an all in one hardware/software package and a philosophy that aims to emulate the cloudless Smartthings of yore (the old lead player in stand alone home automation until they lost their damn minds). It is still a ways DIY, but is not FOSS. Still, active community and tons of supported devices.