ImportController.cs

    public class ImportRequestModel
    {
        public string SupplierId { get; set; }
        public string SeedFilePath { get; set; }
    }

    public class ImportController : ApiController
    {
        public ImportController(IBus bus)
        {
            this.bus = bus;
        }

        readonly IBus bus;

        public HttpResponseMessage Post(ImportRequestModel request)
        {
            var taskId = Guid.NewGuid().ToString("N");

            this.bus.Send<ImportProducts>(message =>
            {
                message.TaskId = taskId;
                message.SupplierId = request.SupplierId;
                message.SeedFilePath = request.SeedFilePath;
            });

            var response = new HttpResponseMessage(HttpStatusCode.Accepted);
            response.Headers.Location = new Uri(string.Format("https://api.example.com/import/status/{0}", taskId));
            return response;
        }
    }