If I purchase an app in the store and have a need to format and reinstall my machine, do I need to…
Adam McNutt
21

That’s a great question! Right now there’s no automated account system, because we don’t store any user data whatsoever on our servers. So there’s no way to associate a purchase with an email address. We’re still working out the details of how to securely and privately handle restoring purchases in a user-friendly way.

However, since this is a common question, there’s documentation on the AppCenter wiki for saving and restoring purchases.