[NathanKP]

Personally I've always favored a JSON HATEOS approach with my API's, where the JSON response contains the actual URL's of the resources referenced, not just URN. Example from one API that I maintain:

https://changelogs.md/api/recently-crawled/

One major advantage of this is that it allows clients to be built which have no hardcoded URL's at all (other than perhaps the top level URI that gives them the list of URL's that the API exposes). This allows the API maintainer to adjust resource paths retroactively, in addition to just exposing an API that is easy to explore.