According to some data mining from the guy who runs SteamDB:
Steam is still working on clip recording. It supports background recording, includes timeline markers in supported games for various events.
Clips can be shared similar to screenshots, via the Steam community.
We don’t actually have any proof that this will be coming to Steam Deck yet, but I’m pretty optimistic that it would.
I recommend clicking through to the article, it has several screenshots showing how the feature will look.
But Live broadcasting/streaming works right from Steam without third party tools. I did that years ago: https://steamcommunity.com/?subsection=broadcasts Or was it not on Linux? Right now I can setup and broadcast and the stream appears as Live (0 viewers). And when clicking the stream in Steam client or in browser, would not start playing. But I could swear it did years ago.
Yeah no it doesn’t work on Linux. AFAIK never has. It’s almost like it’s supposed to, but it doesn’t if you actually try.