The fileTransferReceive notification is received from the peer user only after you submit the action=send request. It's hard to tell why you are getting a 400 error for the action=send request based on the information here. Can you possible add the http request/response starting with the action=invite, receiving the fileTransferInvite response, and then the 400 failure on action=send

Also, the overall protocol flow is also documented at http://developer.yahoo.com/messenger/guide...nsfermanagement

thanks,
Vivek

the uri for file transfer is url: string uri = URL_YM_TRANSFER +
"?&sid=" + SESSION_ID +
"&oauth_consumer_key=" + CONSUMER_KEY +
"&oauth_signature_method=PLAINTEXT" +
"&oauth_nonce=" + randNo.ToString() +
"&oauth_timestamp=" + DateTime.Now +
"&oauth_signature=" + SECRET_KEY + "%26" + OAUTH_TOKEN_SECRET +
"&oauth_version=1.0" +
"&oauth_token=" + OAUTH_TOKEN ;
string postdata = "{\"sendAs\":\"" + myid + "\",\"action\":\"invite\",\"ftSessionId\":\"" + f_sessionId + "\",\"target\":\"" + aYahooContactID + "\",\"files\": [{\"fileName\":\"" + fileArr + "\",\"fileSize\":" + 1168 + "}]}"; filename = "doc.txt"
I appeal httpwebrequest , with x.method = "post", asciiencoding and
byte[] bb = encoding.GetBytes(postdata);
yy.Write(bb, 0, bb.Length);
yy.Flush();

yy.Close();

and i appeal method with notification from where i take fileTransferInvite sessionID
. I appeal again the method with file transfer action: send, httpwebrequest with webrequest.method = "post"". get bytes and appeal again notification. Sometimes i get error 400 if in postdata in filename I send the bytes of the filename and if I send just the filename and I appeal again notification it retunrs filetransferInvite, not filetransferreceive. why?
thx