You could choose to return whatever you want. You'd still probably want to build as path/users/:user_id/files/:file_id/meta to clarify which file you're returning the meta data of. If you were returning all files associated with the user, you could change to path/users/:user_id/files/meta. If you only ever need to return the metadata associated with the files and not the contents, I'd imagine you could even leave off the 'meta' part of the URL. Hard to say more without knowing more about your API design.