That's correct -- your application would create a series of listable tags to group objects together by some convention known and understood by the application.  Unfortunately, there's not a way to automatically have Atmos itself add the tags.  We expose this level of functionality in the API to give the developer maximum flexibility in determining the optimal way to categorize the objects.  I'm not certain as to future functionality where one can list objects by system tags, but it's a good suggestion and I can raise it as an enhancement with the PM team.
So there are APIs to list objects but we need to give a tag.  I was wondering if there is an API or an option to just list the objects belonging to a uid.   The goal is to have a way to list all the objects and their (size, ctime system metadata values).  I'm trying using the Rest WS API to do this with tags value of "size" and get no objects found (1003).  From the DOCS>>> This operation retrieves all object IDs indexed by a given tag. To specify the tag, use the x-emc-tags header; only one tag name/hierarchy may be included. Listable tags are created in a user’s own namespace; hence, they are private to that user. Only objects belonging to the requesting UID are returned. Object Interface—without Metadata Request The x-emc-include-meta header, set to 0, indicates that only object IDs should be returned. GET /rest/objects HTTP/1.1 accept: */* date: Wed, 18 Feb 2009 16:39:49 GMT content-type: application/octet-stream x-emc-date: Wed, 18 Feb 2009 16:39:49 GMT x-emc-tags: size host: 168.159.116.96 x-emc-uid: 33115732f3b7455d9d2344ddd235f4b9/user1 x-emc-signature: ZllFtIyYe6kvqibS9eqcIBpiQ7I= x-emc-include-meta: 1  <<
Atmos API for listing objects w/o giving any tags