This chapter provides details on message types sent between Simplify and the POS. These messages follow the Elavon Gateway API as specified in the Fusebox Integration Guide. The chapter covers both Financial Messages and Non-Financial Messages (Tran Type 36). For additional information on Financial Messages, see the Fusebox industry guides (available via the above link). Message samples in this chapter do not include EMV fields; please refer to the EMV chapter for more information.