I wrote a toy one which works well enough for me: https://github.com/iamsrp/dexter It'll run on a cheap Ubuntu box if you can't get a Pi. And lots of peopl

I wrote a toy one which works well enough for me: https://github.com/iamsrp/dexter It'll run on a cheap Ubuntu box if you can't get a Pi. And lots of people seem to like Rhasspy too: https://github.com/rhasspy/rhasspy which does rather look more polished than my efforts (though I've not tried it myself).