A gateway service platform is disclosed that provides access to a payment processing system via an open network such as the internet. The gateway service platform also provides access to service systems that provide a variety of services and applications offered by or affiliated with the payment processing system. The gateway service platform allows the payment processing system to reach users and to facilitate transactions on a wide variety of devices that may not otherwise be able to connect to payment processing system. Other devices, such as payment terminal devices, can also interact with a payment processing system through the gateway service platform using the same network and protocol. Embodiments of the invention allow devices on these open networks to connect with the payment processing system without having to change the existing infrastructure of the payment processing system.