I’ve been using an input to broadcast to all Google Homes for a while. Recently an update allowed you to designate which room or Google Home you’d like to relay your message through and I’m updated my integration to reflect that new functionality.
I am running Assistant Relay and have it configured as the README describes. I added a new rest_command:
rest_command:
assistant_room_broadcast:
url: http://192.168.1.188:3001/assistant
method: POST
content_type: 'application/json'
payload: '{"command":"broadcast to {{ room }} {{ command }}", "user":"home assistant"}'
and configured a ‘room’ dropdown and a ‘message’ input helper which are displayed in my UI like so:
Submitting the text input field now triggers an automation (I am using AppDaemon but you can use and modify the example from Assistant Relay).
Here is a video of it in action: https://photos.app.goo.gl/BHtKL2o5FdfCaYwt7