If you want to be among the first to test out Fallout 4 mods on Xbox One, you can sign-up starting today.
Fallout 4 Xbox One mods beta sign-ups now open
Today, the publisher announced that registration for the beta is now open. You can register through here, but you'll need a Bethesda account if you don't have one. Put in your Xbox Live Gamertag, and you're all set.
The PlayStation 4 beta is expected sometime after this gets released on Xbox One.
— BethesdaGameStudios (@BethesdaStudios) May 10, 2016
Far Harbor is out May 19. It shouldn't be long after that we start seeing mods on Xbox One.