The announcement post for universal login states the following.

When you log into any Q&A site on the stackexchange.com domain, you will be automatically logged into all other Q&A sites on the stackexchange.com domain + stackexchange.com itself.

  • Area 51 is excluded from this.

Why is Area 51 excluded from universal login?

  • SE seems sparing with programmer resources, and a51 doesn't seem very important for them. If I would be their CEO, I would do it differently, but not I am. :-) The answer below is imho a more discrete formulation with the same meaning.
    – peterh
    Mar 25 '17 at 0:05

According to this comment by Shadow Wizard (September 2016):

As for unified login, the reason is different code base. Area 51 is built with the older version of Stack Exchange "engine", while all other sites with the new version - so they can't be really the same or fully synchronised, as far as I can tell.

I also have a confirmed official source from June 2016 that supports this (in addition to animuson's comment below), where Adam Lear writes (see that post for full context):

... A51 is a completely separate codebase that doesn't have direct access to the database that keeps track of the account sessions. I have some ideas on how we could make the sign-in experience there more seamless, but I need to set some time free to try them out and see what happens.

So yeah, different codebase, no direct access to account sessions.

  • 3
    Yep, the Area 51 code is old and unpleasant, and nobody likes to touch it unless they have to touch it. It's not even fun doing support for it because a lot of the features are the originals that are missing all the functionality we've come to know and love on other sites.
    – animuson StaffMod
    Mar 23 '17 at 23:20
  • @animuson I think maybe the interface between the SE sites could be somehow standardized. It would make not only the a51 easily maintainable, but also to integrate third sites into the system (data SE, for example). Also the discuss.a51 - a51 contact would be more easy.
    – peterh
    Apr 22 '17 at 23:45
  • @peterh It is standardized. The problem is that Area 51 runs off a separate code base because it's a completely different type of site, and it's gotten fairly outdated because no one likes updating it. Data SE is a piece of open source software that will likely never see the full integration into our user system that you desire.
    – animuson StaffMod
    Apr 23 '17 at 0:13
  • @animuson Ok, thanks. I admit maybe extending a51 is not very funny, but considering this stat (you have probably much better ones), and that it significantly influences the SE growth, increasing its priority doesn't seem to me very irrational. If a code is old, it can be refactored, and cleaning up some oldie thing is imho a beautiful task from a programmer view.
    – peterh
    Apr 23 '17 at 0:22
  • @peterh Well part of the reason it got abandoned was that we've been saying for years that we want to ditch the current Area 51 process and remake it from the ground up, and that working on the existing Area 51 system was a waste of time. But I don't think we've gotten any closer to a remake of that system as we were back then when we thought of it. At least I haven't heard anything about it in recent times.
    – animuson StaffMod
    Apr 23 '17 at 0:26
  • @animuson I think it means there were many contradicting ideas and the final compromise was that the a51 remains as it is. But 1) a cleanup / refactor could be still done 2) doing nothing while it is the catalyzator of the network is surely not the best option. It could be said on the "don't change a working system", but it doesn't close out (1). | Btw, if I would be your CEO I would make an arena51, which would be an ordinary SE2.0 site except that you can ask anything, and if enough question is collected about a topic, then a new SE site would be created from them. :-)
    – peterh
    Apr 23 '17 at 1:32

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .