I do not want to have a local broker. I don’t want to add yet another point of failure, so none of the options seem to really replace gbridge for me.
There is (some initial version of) the source code of the backend of Sonoff devices https://github.com/itead/IoTgo
I’m forking it and will do the experiment to integrate it with google home.
It works with websockets instead of MQTT, but ESP8266 devices are perfectly capable of websocket, and using it allows to deploy this in any PaaS like Heroku, and probably under free tier.