1. A method of communicating between two computing devices, the method comprising: receiving, by a first computing device, a request for content that includes an item cached by the first computing device; sending, by the first computing device to a second computing device, the request and an identifier associated with the cached item; receiving, by the first computing device from the second computing device, content generated by the second computing device based on the identifier; combining, by the first computing device, the cached item and the generated content, and sending, by the first computing device, the combined content to a destination.