Methods for updating an application programming interface (API) field of a transaction message may include receiving, with at least one processor, a payment transaction message, wherein the payment transaction message comprises data associated with a payment transaction; determining, with at least one processor, one or more API fields of the payment transaction message based on the data associated with the payment transaction; and modifying, with at least one processor, one or more API fields of the payment transaction message. Methods may also include transmitting, with at least one processor, a modified payment transaction message based on modifying the one or more API fields of the payment transaction message. Systems and computer program products are also disclosed.