Various systems and methods for providing a vending machine interface system are provided herein. A vending machine interface system installed in a vending machine includes a peripheral interface to receive data from a peripheral payment device connected to the vending machine, the data indicating an amount received; an inventory interface to determine a current price of a product; and a vending machine controller interface to transmit a signal to a legacy vending machine controller, the signal causing the vending machine to dispense the product.