>>>Hi,
>>>
>>>I have a source code of an Web API project created with API template in VS 2013. Someone else created this project.
>>>
>>>If I want to see the "flow" of classes/methods when a client calls an endpoint of this Web API (just as a way to learn more). Where (in which class and/or method) would I set the Debugger to stop, so that I can follow from this point? That is, what is the Startup class/method for typical Web API template project?
>>>
>>>TIA
>>
>>Dimitry has given an example of a controller using attribute routing (but the controller will be derived from the ApiController class not Controller).
>>
>>If the site uses convention based routing then there will be a RouteConfig.cs file in the App_Start folder. Inspecting this should allow you to work out which controller and method will be called for a specific url
>
>I use Controller and not ApiController and it works very well.

Hmm. Controller is for System.Web.Mvc - the System.Web.Http.ApiController should be used with Web API - it's better suited to returning serialized data etc.