In embodiments of a programming interface for data communications, a request queue and a completion queue can be allocated from a user-mode virtual memory buffer that corresponds to an application. The request queue and the completion queue can be pinned to physical memory and then mapped to kernel-mode system addresses so that the request queue and the completion queue can be accessed by a kernel-mode execution thread. A request can be received from an application for the kernel to handle data in the request queue, and a system issued to the kernel for the kernel-mode execution thread to handle the request. The kernel-mode execution thread can then handle additional requests from the application without additional system calls being issued.