NET

var uri = new Uri("http://localhost:9000/Het/execute");
var data = "{""Token"":"""",""InputChannel"":""c1"",""OutputChannel"":""c7"",""Message"":""m"",""TimeoutSeconds"":10}";

var request = (HttpWebRequest)HttpWebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "application/json";

var encoding = new UTF8Encoding();
var bytes = encoding.GetBytes(data);

request.ContentLength = bytes.Length;

using (var requestStream = request.GetRequestStream())
{
    // Send the data.
    requestStream.Write(bytes, 0, bytes.Length);
}

request.BeginGetResponse((x) =>
{
    using (HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(x))
    {
        DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(Response));
        var r = ser.ReadObject(response.GetResponseStream()) as Response;
    }
}, null);