Umbrella apps sso in Phoenix?

I have an umbrella app with multiple web phx apps.

I want to be able to allow users to change sites within the umbrella and remain logged in, cross domains.

Will the master_proxy pattern allow this?
Is there some method Phx web apps can share sessions?

Do I need to implement an oauth provider / client or saml or some other sso?

IMHO, yes there is easy way to share session between phoenix app,

  1. my site save 1 cookie value and accessible from the other site (in same domain and same cookie name)
  2. in the backend i use redis for centralized session management, handing login expire, knowing logged username by cookie id, etc
  3. you can easily log out any user just by remove redis key by username / user_id

thanks for the feedback, but I want umbrella apps sso via some kind of phoenix umbrella app feature

I know it can be done with

HTTP protocol does not allow sharing cookies across entirely different domains. You have to work it around somehow.

You can implement it with Cross-Origin Resource Sharing settings (CORS) and piece of AJAX code installed on every site that would check the other site(s) if user is logged in there. Those requests would be able to read cookies set there and would be able to return cookie value / user id you can set then from JavaScript on other domain(s).

Or, you can implement a login page, let’s say on that sets cookie on and briefly redirects to login page which automatically sets cookie for and redirect to and sets cookie for that domain and redirects back user to login success page.

The problem you have on hand is not an umbrella project problem at all. This is precisely the same problem if you have single instance of say Wordpress site using 3 different domains. Sessions handled on are not visible on