The latest Steam Beta version has received support for Nintendo Switch Joy-Con controllers, the company announced via a community post yesterday.
It’s the first time Steam players will be able to use Nintendo Joy-Con controllers, “both individually as a mini-gamepad and combined into pairs.”
This beta version also adds improved support for the Nintendo Online classic controllers, such as the NES, SNES, N64, Sega Genesis controllers.
Some users did mention they are experiencing some issues though. Beta users won’t have to wait anymore, unlike users of the regular version.
[Source]: Steam: Steam Client Beta – August 4 – [Archive].