Contacts API is creating using ASP.NET Core 2 Web API
Uses ASP.NET Core Middleware to check for user key
For detailed write up, please go through http://www.mithunvp.com/create-aspnet-mvc-6-web-api-visual-studio-2015/
For integrating EF Core 2, please refer EF Core 2 with Web API
Implemented Asynchronous ASP.NET Core 2 Web API, read more here
Upgraded to ASP.NET Core 2 Web API and EF Core 2.0