Find the answer to your question
My application called AddItem, but it never received a response. How do I know if the item was added successfully or not?
Your application should pass a unique # (GUID) into the UUID argument of AddItem. If for any reason a response is not received, your application may retry the request. If the item had previously been added, then your application will receive an XML error indicating this condition.
Here is a sample request section with the UUID:
<?xml version="1.0" encoding="utf-8"?>
Here is the error message in the response if the item is already listed with the UUID:
<ShortMessage>Duplicate UUID used.</ShortMessage>
<LongMessage>The specified UUID has already been used; ListedByRequestAppId=1, item ID=4503632367.</LongMessage>