Please note: The iSheet API version 1 provides limited no of methods to work with the iSheets module, please use the iSheet API version 2 which was made available from Collaborate 4.3 and above.

iSheet content can also be fetched by using the isheets XML feed.

In order to find the URL of the XML feed, please select an isheet in isheet admin interface, edit the view of the isheet, (Site Admin - > isheets -> {Add / Edit} view for an Isheet - > Default {click on one of the views}) in the edit interface you will see two XML feeds, the "XML Export Link" works using an IP address white list where as the second one "Sheet view export XML link" requires a valid user session to work. The IP address white list can be updated by raising a support request at http://support.highq.com.
You can also read this KB article to understanding how Isheets XML feed can be used to develop solutions.