Could Discourse offer a StackExchange-like SSO/Federated login service?

[david (David Taylor)]

What you describe was discussed a lot in the beginnings of Discourse. There is a tag for it: #discourse_hub

The most recent topic is from 2014:

Revitalizing the Discourse Hub

The original basic idea of the Discourse Hub have a reserved @username across all Discourse instances, so when someone sees @username on any Discourse forum, they’ll know it is (probably) you! … seems like kind of a bad idea in retrospect. Why? Well, if you run your own Discourse, and your name is @david, you probably want to be called @david, even if some other David reserved the name in Feburary 2013 here on meta. It is your community, after all, who are we to tell you that you can’t use y…

(also, I just noticed that Jeff uses the name @david as an example, many years before I even knew about Discourse )

It is a very cool idea, but there are a lot of roadblocks in the way.