Feeds creates duplicate content each time cron runs I have created a custom feed importer but each time it runs it creates the same content again. How can I make it only create the content once?
In order to update existing nodes, Feeds needs a unique ID to match the source item with the target node. Otherwise, Feeds cannot know which node to update, so it just creates a new one.

When configuring the mapping for your feed importer, choose a unique field in the source, map it to the 'GUID' target and check the 'unique target' checkbox.