SSO or oAuth using my own website as users master db

Hi, I've been searching and reading and I'm a bit confused about where you are at on this topic.

Do you support SSO or oAuth where my site is the master db of user accounts. ie. disabling sign up and sign in - or make that redirect to us. We'd like to autoregisters users, remove them etc., stay in control. We have built our own oAuth2 Provider, if oAuth2 is supported by xenForo.

We are willing to pay for such a solution. Thanks in advance!

Thanks, it would really help if you linked to some of those - I hear you but I find it.

This one, as example, appear to be an oAuth provider, meaning xenforo is master:
A oAuth2 client is what we would need xenforo to offer. But I don't need oAuth, any SSO will do where we are the master (we already have thousands of users that we are looking to build a community and support for). :)