steel
is a text chat client tailored to osu!, which provides the following features below the bare minimum ("send and receive messages"):
download the latest version and extract it into a separate folder. enable automatic updates for better experience.
yes, with Windows/Linux/MacOS support. only Windows is thoroughly tested, so watch out!
one of the heuristics is probably overly cautious, since it can't verify who built the executable. whitelist the application, and both of you should be fine (see example for Windows Defender -- also note the !ml
suffix, which means "machine learning").
https://github.com/TicClick/steel/issues is the place.
right now, it's the IRC gateway, but hopefully the app can be migrated to the websocket API once https://github.com/ppy/osu-web/issues/10118 is resolved.
no: it's stored locally, and only sent to the chat server -- see the source code, or listen to the app's network activity. one to make a note of, though: