It is not "If the client knows nothing about the meaning of the responses" but "The client knows nothing about the API end points associated with this data" Th

It is not "If the client knows nothing about the meaning of the responses" but "The client knows nothing about the API end points associated with this data" This means that if "/api/item/search?filter=xxxxx" returns an array of ids then you don't have to guess that item prices can be fetched by "/api/item/price?id=nnn" but this url (maybe in template form) needs to be provided by either the "/api/item/search?filter=xxxxx" query or another call you have previously executed. So very similarly to how you click on links on a website. You often have a priori knowledge of the semantic of the website, but you visit the settings page by clicking of the settings link, not by manually going to "website.example/settings". PS: these links could be provided by a separate endpoint, but this structure is often useful for things like pagination: instead of manually incrementing offsets each paginated reply can include links for next/previous pages and other relevant links. These need not be full URLs also relative URLs, just URL query fragments, or a JSON description of the query would work (together with a template URL from somewhere else)