https://github.com/drndos/hass-openai-custom-conversation This?

I don’t know about the knx but I believe it comes with a lot of hardware. So I’d be surprised if they didn’t have it.

I can’t get decent voice recognition to work. So no wakeword until I can get a match in the first 3 tries of talking.

I’m not an expert, but if I look around, I see lots of DIYers who use ZigBee and things like that. But professionals use for example KNX. As far as I know KNX is all local, wired and so on; but a multitude more expensive. I guess there are other protocols.

So if money isn’t an issue and I had a new home, I would research KNX first, and eventually add some ZigBee gear.

Also, go for the basics: smart heating, smart switches and smart outlets. That allows the best automations. Maybe add some wires to your doors for openclose detection, power for smart blinds and so on.

That doesn’t give anything to go off… So: https://developers.home-assistant.io/docs/creating_component_index/

I’ve purchased a stereoboomm speaker for cheaper and it has an audio out jack. Very happy with it.