The Appian Web API is a ASP.NET MVC 1.0 RESTful Web Service. You can use it to query the Appian User database for user information. By default, each of the "Actions" on the service return XML responses. If you would like, or require, JSON responses, you must pass a Content-Type: application/json HTTP header with your request.
Click the titles of each section to display usage information.
If you are using the .NET Framework to connect to our services via HttpClient, here are the full classes in c-sharp (they could easily be converted to Visual Basic as well) that are returned from this service. You will need to create these (or a sub-select with only the fields you require) within your solution to utilize the service.