Why I can't make a Binance order using c# with the official Binance REST API?

Question

I am new to StackOverflow but I heard that there are awesome and helpful people who can help me out. 😉

My mission:

• To find a way to make a trade calling the Binance REST API using c#
• Without dlls, using my own code (for speed update)

Now I using the Binance.API package but my bot needs to be a bit faster as its speed is not enough. Also, it would be a great thing to be able to do that without any external sources like dlls. Isn't it? 😎

What I tried:

• Success: I can call the public API without problem with "WebRequest" and which there is no need authentication.

WebRequest webrequest = WebRequest.Create("https://api.binance.com/api/v3/ticker/price?symbol=BTCUSDT");
WebResponse Response = webrequest.GetResponse();
StreamReader reader = new StreamReader(Response.GetResponseStream());
MessageBox.Show(reader.ReadToEnd());

• Success: I can call the REST API without problem with "WebRequest" and which there is need authentication. BUT only the account information.

string dataQueryString = "recvWindow=15000&timestamp=" + Math.Round(Convert.ToDecimal(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalMilliseconds), 0).ToString();
WebRequest webrequest = WebRequest.Create("https://api.binance.com/api/v3/account?" + dataQueryString + "&signature=" + BitConverter.ToString(new HMACSHA256(Encoding.ASCII.GetBytes(tempAPI_Secret)).ComputeHash(Encoding.ASCII.GetBytes(dataQueryString))).Replace("-", string.Empty).ToLower());
webrequest.Method = "GET";
webrequest.Headers.Add("X-MBX-APIKEY", tempAPI_Key);
WebResponse Response = webrequest.GetResponse();
StreamReader reader = new StreamReader(Response.GetResponseStream());
string response = reader.ReadToEnd();
reader.Close();
Response.Close();

• !!! THE PROBLEM !!! I can't call the ORDER REST API with "WebRequest" and which there is need authentication. I tried the code below. (It is called the same way as the account information but with the type of POST and of course with the plus parameters needed)

string dataQueryString = "symbol=BTCUSDT&side=SELL&type=LIMIT&quantity=0.00039&price=38878&newOrderRespType=RESULT&recvWindow=15000&timestamp=" + Math.Round(Convert.ToDecimal(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalMilliseconds), 0).ToString();
WebRequest webrequest = WebRequest.Create("https://api.binance.com/api/v3/account?" + dataQueryString + "&signature=" + BitConverter.ToString(new HMACSHA256(Encoding.ASCII.GetBytes(tempAPI_Secret)).ComputeHash(Encoding.ASCII.GetBytes(dataQueryString))).Replace("-", string.Empty).ToLower());
webrequest.Method = "POST";
webrequest.Headers.Add("X-MBX-APIKEY", tempAPI_Key);
WebResponse Response = webrequest.GetResponse();
StreamReader reader = new StreamReader(Response.GetResponseStream());
string response = reader.ReadToEnd();
reader.Close();
Response.Close();

The returned ERROR code:

'The remote server returned an error: (400) Bad Request.'

I can't understand why this is not working. (I tried to do the order with exactly these parameters from the web client manually and it was successful)

I checked these possible problems:

• I have enough funds on my spot account
• I trying to sell more than the minimum trade amount is

There is the official Binance REST API documentation: HERE

I tried to google it but I couldn't find the solution even here.

Thanks to read it and if you could help me I would really appreciate it. 🙏

If something is not clear please ask it, I will answer!

Answer 1

I was literarly doing the same thing you are a few days ago, except I was using python. I'm also glad to see I'm not the only one who likes coding from scratch.

My solution was to leave the url as is https://api.binance.com/api/v3/account and instead of attaching my order parameters symbol=BTCUSD&side=BUY&etc... onto the url I had to instead encode and send that data through the data parameter of python's built in function urllib.request.Request(url, data, headers)

I don't know C# that well so I wouldn't know how to translate my python code to C#, but I did find this doc link that provides an example on how to send data using a POST request. You could also take a look at my question and answer as another example.