It depends on what you mean by “SSO”:
-
If you’re talking about Setup DiscourseConnect - Official Single-Sign-On for Discourse (sso), then you cannot use it alongside other login options.
-
If you’re talking about OAuth2, OpenID Connect, or any of our other authentication plugins, then yes they can be used alongside each other, and alongside email/password login.
Good news on that front - we’ve recently added invite support for DiscourseConnect
https://github.com/discourse/discourse/commit/355d51afde190b884dbb9b81ebc836a16b48d98c
And for other login methods:
https://github.com/discourse/discourse/commit/ce04db861033c906830fd07ae98b3d0cb375c753
These changes are live in the latest version of Discourse