I am integrating my content provider service as an app in the Schoology directory. I am following the three-legged OAuth protocol that Schoology kicks off with a SAML request and understand how to get each user's SISID. Unfortunately, the SISID is only unique within the context of a district, so I must also fetch each user's district ID before I can conclusively match a user to the account I provisioned through my copy of the district roster. This will then allow me to enforce security for subscription accounts.
What is the recommended strategy for identifying a user's district? Is there an API call that will retrieve the district's Schoology tenant identifier which I can then map to the roster I have imported? Is there a registration workflow when a district adds my content provider app to their account wherein I can map the district identifier? Thanks in advance for your guidance.