: Authorizing transactions in Samsung Pay or other financial services using facial recognition.
If you're looking into Android development: com.sec.facatfunction
While there is no public documentation from Samsung detailing its exact internal code, analysis of its package name and behavior indicates its role: : Authorizing transactions in Samsung Pay or other
The "AtFunction" part of the name refers to . These are standardized commands used to communicate with the phone's modem and hardware for: com.sec.facatfunction