Retrieving attribute ids from project area

Hi all,

is there a way to look up built in and custom attributes without a work item but with a given project area? I want to use the human readable Strings to search the IDs internally for all available attributes in the project area.
For example I want to find the ID (could be something like priority.literal.l01 (=> https://host:port/ccm/oslc/enumerations/_jYoVeSPKEeblWvqjhgHb-Q/priority/priority.literal.l01)) for "Priority" "High". This is want for all kind of things like severity, planned for, filed against, type, state,... As far as I know this is not work item dependent, though all that I find on the internet needs a work item to get the attribute value/id.

I already had a look at this question/answer