The userId on a UserTenant record identifies which User is a member of the tenant organization. Every UserTenant row has exactly one userId, meaning one person, linked to one tenant. When piper checks whether a person is allowed to access tenant data, it looks up the UserTenant record matching their userId and the current tenant. This field is set when the membership is created and does not change.
Technical section
Data model, API, and internals — visible to developers.