How to make my own WebAPI in my class library project?

Im coding a C# class library that can be loaded as a script file to run along side the server application.

i want to code my WebAPI in that class library to update my website about whats happening in the server, however after few hours of digging around i found that i can do that using the ASP.NET WebAPI 2 in a Web application project.

i want to know weather is it possible to use that in my class library or i should make my own WebAPI

My requirement is, i need to GET a json reply through an address like http://localhost:6969