Currently you would have to either expose it on your ViewModel
or derive your own page base class form the NancyRazorViewBase<TModel>
class, and expose it from the RenderContext.Context.Request.Url
property
You can see an example of creating your own page base class here https://github.com/NancyFx/Nancy/blob/master/src/Nancy.ViewEngines.Razor.Tests/GreetingViewBase.cs
I just submitted a pull-request with a code change that makes the following possible from your Razor views https://github.com/NancyFx/Nancy/pull/1633
@Request.Url
@Context.Request.Url
As soon as the pull-request has been accepted you will be able to use it by using our bleeding edge builds https://www.myget.org/gallery/nancyfx
It will then be part of the Nancy v1-alpha release on the official Nuget feed, once we release that