public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{action}.html/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
        }
    }

<modules runAllManagedModulesForAllRequests="true">
      <remove name="FormsAuthentication"/>
    </modules>