@Jonathan5 thanks for the suggestion. I looked through that thread and frankly it looks like a nightmare. What’s more, the members of this association are not using NeonCRM directly to log into anything, only the association managers do. It’s complicated.
I had another thought. I have Discourse set up as invitation-only. Suppose I were to leave it that way, but modify the text of the login page to say something like “please go to my.example.org/discourse-invitation to request an invitation.” And at that URL I would have my script that uses the NeonCRM API to verify the prospective user’s membership, uses the Discourse API to create the user (if verification passes), and sends them the invitation. I think my reasoning here is sound. Am I right?