Systems and methods are provided to enable a user to conduct a transaction using their credentials stored on a secure server computer (e.g., a computer associated with a partner such as another merchant) by merely presenting their authentication data at a physical location via an auxiliary device. An auxiliary device may be provided for interfacing with a partners backend server (e.g., the secure server computer). In some embodiments, biometric authentication may provide a mechanism for a true seamless and potentially frictionless (in the case of modalities that do not require physical contact) interaction. Payment can occur without any need for a card, phone, wearable, or any other user device as long as the auxiliary device is able to recognize the user and retrieve a credential that can be linked to that user.