When using the Admin API that create Attributes to assign a value (Identity) to Client Ids, is this the same attribute used in the Split Targeting Rules from the UI?
The Attributes and Customer Identity in the Admin API is completely different from the Split Targeting Rule attributes, they have no connection and do not affect each other.
The Admin API Attributes are used to assign any existing customer id with identities that show up when a user hovers the mouse on a customer id in the Result tab in the Split UI, see screenshot. They are not involved in the targeting or deciding treatments.
On the other hand, the Targeting rules attributes, are usually entered through the UI, Split accepts any text used for attributes.
When the SDK calls getTreatment method, the code need to create the attribute object, insert the same attribute specified in the targeting rules with their corresponding values and pass the attribute object to the getTreatment method.