[elevation]

A session cookie from app1.domain.com isn’t readable by app2.domain.com. So with plain cookie auth, you have to login to every app individually. Is there a simpler way around this than OIDC?

And what if you want to gate your services to only those users who have an org-issued yubikey? With OIDC you can delegate the device check to a single host (your IdP) and if apps speak OIDC they’ll be protected. That means MFA SSO!

Is OIDC the wrong tool for this job?

[trommlp]

I assume from what you are describing that OIDC is probably just the right tool for this job.

In my problem domain (think internal apps that serve many different purposes with little overlap and a diverse set of users) logging in individually to every single app simply is not an issue, albeit a little annoying).

That being said we do use a single authentication backend across all apps, just not one that is capable of OIDC and is thus a lot more limited in what can be achieved with it.