Silverlight 5

WinRT

public class IncomingWebResponseContext
public WebHeaderCollection Headers { get; }
public HttpStatusCode StatusCode { get; }
public String StatusDescription { get; }

public class OutgoingWebRequestContext
public String Accept { get; set; }
public Int64 ContentLength { get; set; }
public String ContentType { get; set; }
public WebHeaderCollection Headers { get; }
public String IfMatch { get; set; }
public String IfNoneMatch { get; set; }
public String IfUnmodifiedSince { get; set; }
public String Method { get; set; }
public Boolean SuppressEntityBody { get; set; }

public sealed class WebGetAttribute
: Attribute, _Attribute, IOperationBehavior
public WebMessageBodyStyle BodyStyle { get; set; }
public Boolean IsBodyStyleSetExplicitly { get; }
public Boolean IsRequestFormatSetExplicitly { get; }
public Boolean IsResponseFormatSetExplicitly { get; }
public WebMessageFormat RequestFormat { get; set; }
public WebMessageFormat ResponseFormat { get; set; }
public String UriTemplate { get; set; }

public sealed class WebInvokeAttribute
: Attribute, _Attribute, IOperationBehavior
public WebMessageBodyStyle BodyStyle { get; set; }
public Boolean IsBodyStyleSetExplicitly { get; }
public Boolean IsRequestFormatSetExplicitly { get; }
public Boolean IsResponseFormatSetExplicitly { get; }
public String Method { get; set; }
public WebMessageFormat RequestFormat { get; set; }
public WebMessageFormat ResponseFormat { get; set; }
public String UriTemplate { get; set; }

public sealed enum WebMessageBodyStyle
: IComparable, IFormattable, IConvertible
{ Bare, Wrapped, WrappedRequest, WrappedResponse }

public sealed enum WebMessageFormat
: IComparable, IFormattable, IConvertible
{ Xml, Json }

public class WebOperationContext
: IExtension`1<OperationContext>
static public WebOperationContext Current { get; }
public IncomingWebResponseContext IncomingResponse { get; }
public OutgoingWebRequestContext OutgoingRequest { get; }
public virtual void Attach(OperationContext owner);
public virtual void Detach(OperationContext owner);