question. i saw for xbox windows app has mods now?

There was an update for xbox windows 10 app. it said mods support is now added officially.

how do i use it for games like halo mcc?

Faith said:

Hi Doominator. Click on the three dots next to 'play' on the game you want to play within the Xbox app. Click on 'enable mods'. A 'open mods folder' option will appear, and from here you can move the mods you want that you've downloaded, provided there are mods available for the game that supports it. If you don't see these options for Halo: MCC, it means that mods are not supported yet.

Here's a better explanation from Xbox: Xbox Support

i see. thank you. that helps actually. so im guessing future updates will get these games when added throughout the udpates.