<![CDATA[Abstrak Cashless Payment merupakan suatu metode pembayaran non-tunai. Metode pembayaran tersebut sudah diterapkan pada aplikasi perdangan elektronik (e-commerce). Dalam aplikasi e-commerce dapat menerapkan cashless payment dengan integrasi payment gateway. Payment Gateway adalah suatu jalur pembayaran non tunai yang dimana melakukan transaksi secara online dalam aplikasi. Selain aplikasi e-commerce, payment gateway dapat diintegrasikan pada aplikasi pembayaran lainnya seperti pembayaran keterlambatan pengembalian buku di Open Library Telkom University . Proses pembayaran denda saat ini masih memilki kendala yaitu peminjam tidak bisa melakukan secara cash melainkan cashless. Dengan aplikasi yang sudah terintegrasi payment gateway, peminjam dapat melakukan bayar denda secara mandiri atau disebut dengan self payment. Self payment tersebut dilakukan tanpa kontak secara langsung dengan admin. Sebagai konfirmasi ketika sudah selesa i melakukan pembayaran dengan dikirimkan email kepada user melalui Simple Mail Transfer Protocol (SMTP), selain itu transaksi yang sudah dilakukan oleh user akan tersimpan dalam database sebagai riwayat pembayaran. Aplikasi pembayaran keterlambatan buku dilakukan pengujian nilai delay dari client menuju server pada payment gateway dan utillization resource dalam penggunaan CPU, Memory dan Network. Pengujian aplikasi terhadap delay menghasilkan 15.43 ms pada satu device dan 101.29 ms pada dua device, nilai pengujian sudah memenuhi ITU-T G.1010 dalam proses transaksi. Sedangkan utillization resource CPU sebesar 7%, Memory 10% dan Network I/O 151.5 Kbps Kata kunci : Cashless Payment, Payment Gateway, SMTP, Open Library, Delay, Utillization Resource Abstract Cashless Payment is a non-cash payment method. This payment method has been applied to electronic trading applications (e-commerce). In e-commerce applications, cashless payments can be implemented with payment gateway integration. Payment Gateway is a non-cash payment channel which make online transactions in the application. In addition to ecommerce applications, payment gateway can be integrated into other payment applications such as late payment for returning books at the Telkom University Open Library.The process of paying fines still have obstacles, when patron can’t transaction via cash, but cashless. With an application that has an integrated payment gateway, patrons can pay fines independently , which is known as self payment. Self payment not made directly interacting with admin. As confirmation when the payment has been completed by sending an email to the user via the Simple Mail Transfer Protocol (SMTP), and transactions that have been made by the user will be stored in the database as payment history.The book delay payment application has been testing for delay from the client to the server on the payment gateway and resource utilization in CPU, Memory and Network usage. Application testing for delay produces is 15.43 ms on one device and 101.29 ms on two device the value of testing has met the ITU-T G.1010 standard of delay in process transactions. Meanwhile value of utilization resource for CPU is 7%, Memory 10% and Network I/O 151.5 Kbps. Keywords: Cashless Payment, Payment Gateway, SMTP, Open Library, Delay, Utillization Resourc]]>
