In the previous part of this article and video series you developed a TypeScript class that invokes an ASP.NET Core Web API using XMLHttpRequest object. Recollect from the previous part that the EmployeeApiClient class expects a few callback functions. These callback functions receive the response returned by the Employees Web API and display it on to the web page. In this part you will create another TypeScript class that houses those callback functions. You will also create the Employees Web API that performs the CRUD operations. Finally, you will test the functioning of both the TypeScript classes (and the Employees Web API) by calling their methods from a web page.