.NET C# Integration

HttpWebRequest request = WebRequest.Create( "https://api.goodgrids.com/api/convert/v1/csv-to-excel/3a6c0d9ac7c74d" ) as HttpWebRequest;

// Set type to POST
request.Method = "POST";
request.ContentType = "text/csv;";

// Create a byte array of the csv_data we want to send
byte[] byteData = Encoding.UTF8.GetBytes( csv_data.ToString() );

// Set the content length in the request headers
request.ContentLength = byteData.Length;

// Write data
using ( Stream postStream = request.GetRequestStream() )
{
    postStream.Write( byteData, 0, byteData.Length );
}

// Get response
using ( HttpWebResponse response = request.GetResponse() as HttpWebResponse )
{
    Stream responseStreamContainingExcelFileData = response.GetResponseStream();
}