This example uses the Elmah.MVC package for loggine MVC exceptions and Elmah.Contrib.WebApi package for logging Web API exceptions. For the Jobcast project, I found that Elmah.MVC interfered with 401 responses as soon as it was installed, so I used the standard elmah package instead.

Resources:

• Why you need both Elmah.MVC and Elmah.Contrib.WebApi: http://dbarrowstechblog.blogspot.co.uk/2015/03/elmah-aspnet-webapi-tip.html
• Elmah.MVC is better than Elmah.Contrib.MVC: http://stackoverflow.com/a/15583497/188740