ServiceStack: Send JSON string instead DTO via POST - servicestack

Question

I would like to send a string (JSON formatted) to my webservice instead using a DTO.
var client = new JsonServiceClient(absoluteUrl);
client.Post<T>(absoluteUrl, data);
But, after to do change my data (DTO object) to a JSON string, I'm getting a ServiceStack Exception: Internal Server Error. Looks like the ServiceStack Post/Send method changes my JSON request.
Is it possible or is there any way to avoid it? Someone else had the same issue?
UPDATE 1: I'm using this approach because of the OAuth authentication. I'm generating a HMAC by request.
Thanks.

Answer 1

You can use HTTP Utils to send raw JSON, e.g:
var response = absoluteUrl.PostJsonToUrl(data)
.FromJson<T>();
ServiceStack's .NET Service Clients provide Typed API's to send Typed Request DTO's, it's not meant for POST'ing raw strings but I've just added support for sending raw string, byte[] and Stream in this commit so now you can send raw data with:
var requestPath = request.ToPostUrl();
string json = request.ToJson();
var response = client.Post<GetCustomerResponse>(requestPath, json);
byte[] bytes = json.ToUtf8Bytes();
response = client.Post<GetCustomerResponse>(requestPath, bytes);
Stream ms = new MemoryStream(bytes);
response = client.Post<GetCustomerResponse>(requestPath, ms);
This change is available from v4.0.43+ that's now available on MyGet.
Sharing Cookies with HttpWebRequest
To have different HttpWebRequests share the same "Session" you just need to share the clients Cookies, e.g. after authenticating with a JsonServiceClient you can share the cookies with HTTP Utils by assigning it's CookieContainer, e.g:
var response = absoluteUrl.PostJsonToUrl(data,
requestFilter: req => req.CookieContainer = client.CookieContainer)
.FromJson<T>();