Install

You need to follow this to add the correct repository before installing.

Next you'll need to enable 32 bits repositories (thanks Valve...) Go to /etc/pacman.conf and uncomment

#[lib32]
#Include = /etc/pacman.d/mirrorlist

Install and be careful to choose the correct vulkan driver.

doas pacman -S steam

Steamguard

yay -S steamguard-cli

Run

The steam client is only working with X11 currently so you need xorg-xwayland to launch it.

Xwayland :1 | DISPLAY=:1 steam

You might need to enable user namespace

doas sysctl kernel.unprivileged_userns_clone=1

Gamescope

doas pacman -S gamescope

Add this to your steam game launch options

gamescope -- %command%