The original posting of Rhasspy over on the Home Assistant forum contained the following statement as planned features:
A chat plugin for driving rhasspy via text instead of speech from your phone (probably using matrix chat).
Does anyone have currently a setup that integrates both Rhasspy and e.g. the Matrix chat server?
Since Rhasspy as well as the Matrix integration in Home Assistant both support sending events, perhaps we can react to these events in an automation and invoking e.g. an intent script.