See the ListBasedPublishSubscribe WCF sample for an example of this. 2. Have clients implement services at endpoints that listen for events, have clients send those endpoint addresses to the eventing service to register them, and have the eventing service make event calls to those endpoints. Friday, March 16, 2007 5:39 PM All replies 2 The Bean Trader sample is only a small app, but hopefully this walk-through demonstrates the sorts of changes needed to get WCF services working on .NET 6 with CoreWCF. The WCF service implementations were unchanged except for referencing some different namespaces and most of the configuration xml was re-used. Calling services asynchronously. Calling services using client channels. Obtain the Service Contract, Bindings, and Addresses. In WCF, services and clients model contracts using managed attributes, interfaces, and methods. To connect to a service in a client application, you need to obtain the type information for the service contract. alter the contract to Async without breaking the interface; convert a sync method to async; call an async method from a sync method; Note: .NET Framework 4.6.1 or higher is needed to make use of the async and await keywords. Let's tackle these points in order. Making Contract Async. Change the return type T (if any) of the interface contract The Asynchronous call for WPF works around the AsyncPattern property. see difinitions. AsyncPattern - Provides for the implementation of an asynchronous process on the server, client, or both tiers. This feature aids .NET clients in supporting operations with the efficiency of using a single client thread. Tuesday, March 11, 2008 7:57 AM Windows Communication Foundation (WCF) is a framework for building service-oriented applications. Using WCF, you can send data as asynchronous messages from one service endpoint to another. A service endpoint can be part of a continuously available service hosted by IIS, or it can be a service hosted in an application. The recommended practice is using Async await . in your case it should be like this var result = await client.LoginAsync ("user", "password"); of course the LoginAsync should should a public method that returns Task From the link you shared , check the section 3. The task-based asynchronous pattern . Task-based asynchronous programming is now simplified and streamlined in .NET 4.5 by the keywords "await" and "async". Sample WCF Application Step 1: Open VS2012 and create a blank solution, name it "WCF_Task_Based_WCFService". In this solution add a new WCF Service application project targeting the .NET 4.5 Framework. Asynchronous operations allow a client to send a request to the server and the server callback to the client when the operation is complete.In this way, the client can free himself to do other th in gs and gets around any message timeout issues. In WCF applications, asynchronous requests in two ways: In our product we needed to ensure backwards compatibility with older clients and to my suprise: Making the operations async don't break the WCF contract!. So - a short example: Sync Sample. The sample code is more or less the default implementation for WCF services when you use Visual Studio: