How to programmatically connect to QuickBooks Online Edition (QBOE)

Here are all the steps to connect to QuickBooks Online Edition (QBOE) and retrieve some data.  Special thanks to Keith Palmer for his comments, answers, and his Consolibyte Solutions Website which really helped me get this working.  Originally posted on StackOverflow: Connecting an ASP.NET application to QuickBooks Online Edition.

1. Register your application at http://appreg.quickbooks.com. This will give you your App ID and Application Name. Use these settings:
• Target Application: QBOE
• Environment: Production
• Application Type: Desktop
• (using Desktop made things much easier as far as not needing certificates)
• A verification key will be sent to your email address which you need to enter on page 2 of this wizard.
2. Set up your QBOE Connection. Once you finish registering your application in Step 1, you will then have an Application ID. Use this ID in the url below to set up your QBOE Connection:
• https://login.quickbooks.com/j/qbn/sdkapp/confirm?serviceid=2004&appid=APP_ID
• NOTE: Make sure to replace APP_ID in the above url with the Application ID that was created when you registered your application.
• The wizard will take you through the following steps:
1. Specifying a name for your connection.
2. Granting Access Rights - I gave All Accounting rights since this was easiest.
3. Specify Login Security - I turned Login Security Off. This is important since it makes submitting the xml to the QBOE much easier since you do not need to get a session ticket for each user.
4. You will then be given a Connection Key.
3. At this point you now have the 3 important pieces of information in order to gain access to your QuickBooks Online Edition (QBOE) account.
• Application Name
• Application ID
• Connection Key
4. Post the XML to QBOE with the 3 pieces of access information and the actual request into your QBOE database. Here is sample c# code that will post to the QBOE gateway. This will return all customers in your QuickBooks database. Make sure to update the xml below with your Application Name, Application ID, and Connection Key.

string requestUrl = null;
requestUrl = "https://apps.quickbooks.com/j/AppGateway";

HttpWebRequest WebRequestObject = null;
StreamReader sr = null;
HttpWebResponse WebResponseObject = null;
StreamWriter swr = null;

try
{
    WebRequestObject = (HttpWebRequest)WebRequest.Create(requestUrl);
    WebRequestObject.Method = "POST";
    WebRequestObject.ContentType = "application/x-qbxml";
    WebRequestObject.AllowAutoRedirect = false;
string post = @"<?xml version=""1.0"" encoding=""utf-8"" ?>
<?qbxml version=""6.0""?>
<QBXML>
<SignonMsgsRq>
<SignonDesktopRq>
<ClientDateTime>%%CLIENT_DATE_TIME%%</ClientDateTime>
<ApplicationLogin>APPLICATION_LOGIN</ApplicationLogin>
<ConnectionTicket>CONNECTION_TICKET</ConnectionTicket>
<Language>English</Language>
<AppID>APP_ID</AppID>
<AppVer>1</AppVer>
</SignonDesktopRq>
</SignonMsgsRq>
<QBXMLMsgsRq onError=""continueOnError"">
<CustomerQueryRq requestID=""2"" />
</QBXMLMsgsRq>
</QBXML>";

    post = post.Replace("%%CLIENT_DATE_TIME%%", DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ss"));
    XmlDocument xmlDoc = new XmlDocument();
    xmlDoc.LoadXml(post);
    post = xmlDoc.InnerXml;
    WebRequestObject.ContentLength = post.Length;
    swr = new StreamWriter(WebRequestObject.GetRequestStream());
    swr.Write(post);
    swr.Close();
    WebResponseObject = (HttpWebResponse)WebRequestObject.GetResponse();
    sr = new StreamReader(WebResponseObject.GetResponseStream());
    string Results = sr.ReadToEnd();
    }
finally
    {
        try
        {
            sr.Close();
        }
        catch
        {
        }

    try
    {
        WebResponseObject.Close();
        WebRequestObject.Abort();
    }
    catch
    {
    }
}

 

• Couple things to note:
• The qbxml version needs to be 6.0 (even though the IDN Unified On-Screen Reference shows 7.0).
• The onError="continueOnError" attribute is required.
• Setting the WebRequestObject.ContentLength property is required.
• Content Type needs to be "application/x-qbxml".
• And finally I received many "The remote server returned an error: (400) Bad Request." exceptions which were not helpful at all but in the end I was able to trace them to something wrong with the xml. So if you get this exception look to your xml as the source of the problem.