Desire2Learn - Cannot retrieve what's passed as the "user_id" value in an LTI post from the Valence API

Question

I was hoping someone could give me some insight into this, basically I was hoping to find a way to either return this value for a given user via the Valence API or calculate this value based on the user's primary key that's passed over in an LTI post.

What is sent in the LTI POST as the user identifier: user_id=815dc366-c443-4023-a13c-9c43e9edce52_239393

What's returned from the Valence API as the user identifier: Enrollment.ClasslistUser.Identifier=228588

Answer 1

The Brightspace application APIs currently don't provide a way to retrieve the LTI user identifier for a user. The LTI user identifier sent in the user_id LTI launch property is currently only available via LTI launches.

Additionally, the LTI user_id values that Brightspace assigns to users are intentionally opaque and not constructable by clients. (It's true that some Brightspace instances send the D2L ID as a component in the LTI launch user_id property, but you should not depend upon that.)