A minimal media type: JSON with hypermedia controls
JSON Hypermedia Controls (JSON-HC) is a standard which establishes conventions for expressing hypermedia controls in JSON (RFC4627).
The Hypermedia Controls of JSON-HC provide a way to figure out which Actions are possible with a Resource Object, what is the self URL of the Object and of which profile is the Resource Object.
The official site of json-hc is https://json-hc.org.
The latest internet draft is published at https://tools.ietf.org/html/draft-schuetze-json-hc and is maintained at https://github.com/json-hc/json-hc-specification/blob/master/json-hc.md in markdown.
application/vnd.hc+json
There will be a registered media-type at IANA: application/vnd.hc+json
If you want to compare json-hc to mike kelly's awesome hal or collection+json, I created a document called json-hc-vs-other-media-types.md.
There is also an example api built with json-hc, which describes a game server api at gameserver-json-example.md.
The maintainer and creator of json-hc is dracoblue.