On February 5, 2013, the Secretary of Veterans Affairs (VA) announced that the VA would use Veterans Health Information Systems and Technology Architecture (VistA), the VA’s open source Electronic Health Record (EHR), in its “API Exposure” to an interoperable Electronic Health Record (iEHR) with the Department of Defense (DOD).

In order to prepare VistA to serve as the foundation of the interoperable electronic health record, VistA must be updated to modernize the way in which other products connect to it. VistA API Exposure 1.0 is the first step in this modernization.

Modernizing VistA means exposing existing VistA Application Program Interfaces (APIs) in the selected API Exposure domains as services. In increment 1 selected APIs in Kernel, Mail Man and File Man will be exposed as Remote Procedure Call (RPC) web services on an Enterprise Service Bus. Exposing the APIs as web services will enable the APIs to communicate with any other service within reach of the network.

The included Software Design Document (SDD) provides the functional and technical design that will be implemented for exposing the VistA APIs as web services.