More than often developers test API, either through a browser or using some clients such as POSTMAN, Advanced Rest Client (ARC). To publish the functionality of the API to the public, we tend to expose the methods and descriptions, and associated data structure through some means. To complement, either or both functionalities, Swagger becomes handy. Swagger UI is a tool that can be used across the API lifecycle. Swagger UI provides, among others, easy to navigate documentation and /or visualization of API resources and enables interaction with API from within the application making the development and testing effort, as well as end-user experience seamlessly smooth. In this presentation, I will discuss how to implement swagger in API and exemplify some use cases showcasing a simple demo .Net Core 2.2 Web API application written in C# using Visual Studio 2017 IDE.