is modding available for game pass games??

Currently, I don't believe this is possible but may be in the works for some games.

Hi zero,

Thank you for posting on the Xbox forums.

Unfortunately it is not possible to mod games downloaded through the Xbox Game Pass subscription. The program files for those game are in a folder named WindowsApps which is locked from accessing. Also, modding is not allowed to discuss on the Xbox forums,
per the
Xbox Forum Guidelines, so we will also be locking this thread. If you have any different questions or concerns please create a new thread with the guidelines in mind and we will be happy to answer. Thank you for understanding, have a great day!

Some games can be modding.

https://www.reddit.com/r/pcgaming/comments/cf5fgv/work_on_moddable_win_store_apps_seem_to_be/

https://www.thegamer.com/pc-xbox-game-pass-games-finally-getting-mod-support/

Hello again, I don't know which game was with the mods enabled, but ideally contact the developer to check if they disabled the in-game mods available in the Game Pass.

You cannot use any mod or add on not made available in the in game store with the game pass or Xbox version