By default, OpenRasta registers some useful implementations of services for you which you can access by simply adding a parameter of the correct service type to any constructor in any OpenRasta object, be that a pipeline contributor, a URI decorator, a codec or a simple handler. These services are exposed through the OpenRasta.Web namespace.

Here's a handy table of some of the most useful singletons/per-request services you can request in your constructors:

Service	Description
ICommunicationContext	The OpenRasta "God object", similar in nature to ASP.NET's HttpContext. Accrues useful information through the lifetime of a request.Try to find another, more specific available interface before using this - it has the same level of mutable state as the aforementioned HttpContext!
IRequest	Roughly similar to ASP.NET's HttpRequest (usually seen on HttpContext.Current.Request). Allows access to the request message, containing query string, URI and so forth
IResponse	Contains all data related to the response being sent back to the client. Roughly similar to ASP.NET's HttpResponse.
IHost	Host-specific detail - application's virtual path
ILogger and ILogger<TLogSource>	Provides access to the logging infrastructure
IMetaModelRepository	Contains a full MetaModelRepository?, which allows you to reason about the relationships between things like handlers, resources, codecs and URIs
IUriResolver	Allows resolution of URIs to ResourceMatchs and allows manual creation of URIs in code
IHandlerRepository	Single repository of all registered handler
ICodecRepository	Single repository of all registered codecs