The Umbrella Faces Profile API (Sync API), which utilizes a pre-shared secret key.

If this Sync API is chosen: Will you need a one-way interface from Umbrella to your application or a bidirectional interface

Documentation: 

https://docs.google.com/document/d/1_d9qufFmCRH8pPh1MPHDmFK0TZdayxvF20sLEb3Om5k/edit?usp=sharing