Developing payment terminal applications

The method of development of third-party Android applications on the NEXGO payment terminal does not differ from the development on regular Android devices (smartphone). The communication between the third party application and the payment application is realized by means of an intent call according to the "Payment application" specification. The interface offers the invocation of financial operations such as payment, return, cancellation of the last transaction or service operations such as closing, handshake or parameter update. The payment application returns the result of the operation to the parent application in JSON format after performing the operation.

The third-party application can also access terminal peripherals such as a printer. Access is done using the NEXGO SDK, where it is possible to access individual peripherals via an API.

For security reasons, the distribution and installation of third-party apps is handled differently from regular Android devices. Any production version of the app is distributed and continues to be updated using our special pre-installed app, not from the standard Play Store. Based on the serial number of the payment terminal in question, the corresponding app will be installed or updated. In case of a request for distribution or update of the application, the application must be provided to our company in .apk format. We will sign the application with a special security certificate and distribute it to the required payment terminals.

The above procedure is valid for production payment terminals. For development purposes, it is possible to provide a payment terminal in the so-called debug mode, using which it is possible to develop and upload applications locally in the usual way valid for standard Android OS devices.

The numeric currency code (currencyCode) is based on ISO-4217, we currently support EUR (978) and CZK (203). The complete list is for instance here. 

Download the API here.
(payment)

NEXGO API download here.
(printer, QR reader)