Using Meteor as an SSO/SAML provider?

Has anyone ever setup Meteor to be an SSO provider? I see lots of resources for logging into a Meteor-based app w/ third-party SSO providers (like here, here and here), but haven’t found any solutions on how to use Meteor as the source for other sites that allow SSO / SAML authentication.

We do a lot of post-signup validation on our users, and I’d like to use that to offer secure signups for other services.