Patent attributes
A computer-implemented method for an extensible point-of-sale device is disclosed. The method includes registering a third-party application to be notified of a transaction change on the point-of-sale device. The method also includes displaying a user interface to a user during a purchase transaction on a display of the point-of-sale device using one of a register module and a payment module. The method also includes receiving the transaction change via the user interface of the point-of-sale device. The method also includes broadcasting the transaction change to a set of registered applications that includes the third-party application. The method also includes taking an action that modifies the purchase transaction using the third-party application in response to the broadcasting.