WebApi.SelfHost

using System.Web.Http;
using System.Web.Http.SelfHost;

namespace Workflow.Console
{
    class Program
    {
        static void Main(string[] args)
        {
            var config = new HttpSelfHostConfiguration("http://localhost:8080");

            config.Routes.MapHttpRoute(
                "API Default", "api/{controller}/{id}",
                new { id = RouteParameter.Optional });

            using (var server = new HttpSelfHostServer(config))
            {
                server.OpenAsync().Wait();
                System.Console.WriteLine("Press Enter to quit.");
                System.Console.ReadLine();
            }
        }
    }
}

using System.Collections.Generic;
using System;
using System.Web.Http;
using System.Threading;
using System.Threading.Tasks;

namespace Workflow.Console
{
    public class DocumentUploadController : ApiController
    {
        public Guid Post([FromBody] DocumentRequest reportData)
        {
            var id = Guid.NewGuid();
            Task.Factory.StartNew(() => CreateReport(id.ToString(), reportData.Parameter1));
            return id;
        }

        private void CreateReport(string key, string documentData)
        {
            Thread.Sleep(5000);
            DocumentDownloadController.Cache.Add(key, "GENERATED DOCUMENT:  " + documentData);
        }
    }

    public class DocumentDownloadController : ApiController
    {
        public static Dictionary<string, string> Cache = new Dictionary<string, string>();

        public DocumentResponse Get(string id)
        {
            string document;
            var response = new DocumentResponse { Id = id };
            if (Cache.TryGetValue(id, out document))
            {
                response.IsAvailable = true;
                response.Document = document;
            }
            else
            {
                response.IsAvailable = false;
            }
            return response;
        }
    }

    public class DocumentRequest
    {
        public string Parameter1 { get; set; }
    }

    public class DocumentResponse
    {
        public string Id { get; set; }
        public bool IsAvailable { get; set; }
        public string Document { get; set; }
    }
}

With XML:

or add this line to Program Main and you can remove the namespace from the xml:

config.Formatters.XmlFormatter.UseXmlSerializer = true;