WebAPI Default URL - rest

Question

I am looking at using WebAPI to create a Restful API. I want to create a launch url to provide URLs to the other portions/entities of the API. The obvious place to do this is ~/api/ however I cannot seem to wire up a route that will not give a 403 result. Any ideas?
EDIT: Just to be a bit clearer. I know how the default routing works in WebAPI, I.E. if I create a CustomersController that inherits from ApiController I can get there using ~/api/customers. What I want is a step before that where I could go to ~/api/ and would get a result a bit like:
[
{ Title: 'Customers', Url: '~/api/customers' }
]
I want this as my understanding is that RESTful services are metadata (think that the term) driven (basically discoverable and provide links to other resources in result). So there should be a single source url that points to all other resources in the API.

Answer 1

All you need to do for this is to add a new route which handles ~/api specifically.
In your project you will notice in the Application_Start method in the Global.asax a call is made to WebApiConfig.Register(GlobalConfiguration.Configuration), the WebApiConfig class is included in your project in the App_Start folder (along with various other config classes). If you look at the implementation of the Register call you will see that's where the ~/api/controller route is actually setup i.e.
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
In order to make ~/api discoverable all you need to do is introduce a new route before the default which handles any calls to ~/api e.g.
config.Routes.MapHttpRoute(
name: "DiscoverableApi",
routeTemplate: "api",
defaults: new { controller = "Discoverable", }
);
Then add an ApiController to handle that call e.g.
public class DiscoverableController : ApiController
{
// GET api/values
public IEnumerable<string> Get()
{
return new string[] { "/users", "/photos", "/history" };
}
}
If you don't want to hard-code your URLs you will most likely need to look at something like Reflection to enumerable all the available ApiController's and their reachable endpoints (i.e. actions).

Answer 2

Take a look at the Microsoft ASP.NET Web API Help Page package from NuGet. Out of the box you can create a list of all your API endpoints which are returned as an MVC View. However you could customise it to return Json instead. You can also configure it to hang off any route you want, i.e.
api.mysite.com/help
myapi.com/api
etc