marc_s marc_s - 7 months ago 124
JSON Question

Telling RestSharp *not* to add a specific HTTP header

I am trying to call a REST service from a C# ASP.NET 4.0 application using RestSharp.

It's a fairly straightforward POST call to a https:// address; my code is something like this (

is a plain simple DTO with about four or five
properties - nothing fancy):

public CheckStatusResponse CheckStatus(CheckStatusRequest request) {
// set up RestClient
RestClient client = new RestClient();
string uri = "https://.......";

// create the request (see below)
IRestRequest restRequest = CreateRequestWithHeaders(url, Method.POST);

// add the body to the request

// execute call
var restResponse = _restClient.Execute<CheckStatusResponse>(restRequest);

// set up request
private IRestRequest CreateRequestWithHeaders(string uri, Method method) {
// define request
RestRequest request = new RestRequest(uri, method);

// add two required HTTP headers
request.AddHeader("Accept", "application/json");
request.AddHeader("Content-Type", "application/json");

// define JSON as my format
request.RequestFormat = DataFormat.Json;

// attach the JSON.NET serializer for RestSharp
request.JsonSerializer = new RestSharpJsonNetSerializer();

return request;

The problem I'm having when I send these requests through Fiddler to see what's going on is that my request suddenly gets a third and unwanted HTTP header:

POST https://-some-url- HTTP/1.1
Accept: application/json
User-Agent: RestSharp/
Content-Type: application/json
Host: **********.com
Content-Length: 226
Accept-Encoding: gzip, deflate <<<=== This one here is UNWANTED!
Connection: Keep-Alive

I suddenly have that
HTTP header, which I never specified (and which I don't want to have in there). And now my response is no longer proper JSON (which I'm able to parse), but suddenly I get back gzipped binary data instead (which doesn't do real well when trying to JSON-deserialize)....

How can I get rid of that third unwanted HTTP header?

  • I tried to set it to something else - whatever I enter just gets appended to those settings

  • I tried to somehow "clear" that HTTP header - without any success

  • I tried finding a property on the RestClient or the RestRequest classes to specify "do not use GZip"


Looking at the sources (Http.Sync.cs and Http.Async.cs) of RestSharp you can see that these values are hardcoded:

webRequest.AutomaticDecompression = 
    DecompressionMethods.Deflate | DecompressionMethods.GZip | DecompressionMethods.None;

There is also an open issue that describes this problem. It was opened August 2014 but still not solved. I think you can leave a comment there and maybe they will pay attention.