Note: Please ensure that you have access to an experienced JavaScript developer, because Marketo Technical Support is not set up to assist with troubleshooting custom JavaScript.
If you're trying to use the Munchkin API but not having any success, try these tips:
Make sure you include the required lines of Munchkin Javascript on pages with API calls. You can find the javascript in the Admin section under Munchkin Setup.
In the Munchkin Setup page, check the box that says Enable Munchkin API, put in a private key (which can be any text), and click Save.
Use Firebug on Firefox or enable IE JavaScript debugging to check for JavaScript errors. Any JavaScript errors that occur -- anywhere on the page -- could prevent Munchkin from working.
Check and make sure that any quotation marks or other characters that require escaping are properly escaped. See this document for more.
In your Javascript, you must call mktoMunchkin() before you use any other Munchkin API calls.
Use a web traffic capturing program like Firebug (for Firefox) or Fiddler. The return code from the API call may have useful information to help you diagnose the issue.
Check to make sure you have only a path listed in the url parameter -- no ", no domain, and no URL parameters.
This could be caused by a few issues:
Include an email address
Email address is required when using the associate Lead call. If you don't use this, the call will always fail.
Marketo expects the labels (like "Email" and "FirstName") in a specific format. You can get these labels in the Field Management page of the Admin section. When you get there, click the Export Fields button. The spreadsheet will have the API names for your fields.
Check the hash value
The hash value is the SHA1 hash (non-HMAC version) of your API Private Key (not your Munchkin ID) concatenated with the lead's email address, as in your-secret-keyemail@address.com. The hash value must be lowercase.