static void Main(string[] args) { var serviceUri = new Uri("http://localhost:61317/odata"); var context = new Default.Container(serviceUri); // context.Products.ByKey(1).GetValueAsync().Wait(); var product = new Product { Id = 99, Name = "Product 99" }; context.Configurations.RequestPipeline.OnEntryStarting(args => { if (product.GetType().IsAssignableFrom(args.Entity.GetType())) { List <ODataProperty> entryProperties = args.Entry.Properties as List <ODataProperty>; entryProperties.Add(new ODataProperty { Name = "SalesDescription", Value = new ODataPrimitiveValue("Product 99 sales description") }); } }); context.AddToProducts(product); context.SaveChangesAsync(SaveChangesOptions.None).Wait(); }