- interesting, how does it interface with hardware,

- is it a low level c API or something that has directly interface to communicate with arduino, raspberry etc?

- what kind of devices can you use it with?

Not sure about those, I've only uses it with home assistant and virtual logic and communication. The most I use it when it comes to hardware is sending commands to my phones/tablets/laptops to run on/off, open urls, toggle wifi/Bluetooth, etc.