Microsoft has included a new feature named Azure API Apps as part of the Azure SDK 2.5.1 release. This feature raises the capabilities of ASP.NET Web API. It is also possible to extend this feature with Swagger metadata while providing a simple to manage interface in the Azure Portal.
With the help of Azure API Apps, you will be able to extend API with authentication and no code changes or generate an SDK for your API with a few clicks. Microsoft has provided full definition of API apps and their capabilities on the official Azure documentation.
API Apps resides in a single host App Gateway, which manages add-on functionality such as authentication and update policies for the API. Moreover, Gateways are contained within a standard Azure Resource Group.
API apps basically make use of connectors to access SaaS (software as a service) platforms such as Office 365 and Salesforce. You will be able to review the Swagger metadata for your app by navigating a web browser to the default web location of /swagger/docs/v1 in your compiled and running project in Visual Studio.
Jeffrey T. Fritz, Partner, Microsoft has provided code sample of ASP.NET API Controllers and the corresponding swagger format.