The Publish to GSA (Google Search Appliance) publisher will post documents to GSA index through the URL: http://<appliance-hostname>:19900/xmlfeed as described by Google in the Feeds Protocol Developer's Guide. 

Features

Some of the features of the Publish to GSA publisher include:

• Customization of the feed for the GSA by editing the XSLT file.
• Is connector independent
• Runs from any machine with access to the GSA.
• Mark all content as public (for troubleshooting mainly). Default behavior is: secure if ACL's are part of the data extracted from the file.