Hi there. I plan on starting a site that will have some user overlap with an already-existing discourse site. I’d like for my visitors to be able to create accounts with their creds from the other discourse site. How would this be done?
I’d suggest Using Discourse as a SSO provider.
So, going down this path will allow me to add a new button to my login buttons (fb, discord, gihub, google, etc.), and this new button will be for a different discourse forum, which I don’t own and operate?
Yes, this is one possible setup for the official WP Discourse plugin (just an example of the SSO provider / SSO client relationship).
If this site you’re starting is another Discourse instance it may be possible, too, but I don’t know if there’s any documentation here on meta on this approach.
This is not possible. You can’t get private user data from any external website without an additional security step, in this case in the form of the
sso provider secrets used when doing the SSO flow.
You might also consider a dedicated access and identity manager like http://auth0.com/ if you believe things might expand even more down the line …
No. Sso would be the only provider. And if you don’t have control of the other site then there is no way that you can use it for authentication.