Like the title says I am trying to understand how these things should work together. Part of my issue is I don’t have a good mental model on the Flatpak permissioning / sandbox model. My use case is running a game on Lutris, which is a Flatpack, and using my package install of Mangohud. I am also curious if I should using a Flatpak version of Mangohud instead of the package installed version, and understanding how I would set up Steam as a Flatpak in the future when I switch away from the packaged version.
Thanks for any helpful tips or links you can provide.


Here is my understanding of this now I’ve got everything working on my Flatpak install of Steam:
MangoHud
org.freedesktop.Platform.VulkanLayer.MangoHud. There are multiple versions and you need the one that matches the Steam runtime that you can see by runningflatpak list --app --columns=application,runtime | grep -i "steam"MANGOHUD=1 %command%to the Steam launch options of the gameMANGOHUD=1to the Steam FlatPak to get this working in every game by defaultGamemode
gamemoderun %command%to the launch options to run the game with Gamemode enabledEdit: You actually DO need to install Mangohud and you need to match the Steam runtime version.