I do that for my backends. On the HTTP request, the client sends a `?fields=encodeURIComponent(<JSON>)` query parameter to the server. If `fields` is present,

I do that for my backends. On the HTTP request, the client sends a `?fields=encodeURIComponent(<JSON>)` query parameter to the server. If `fields` is present, then the API sends back the pruned version of the REST API. If `fields` is not present, then all the fields are sent back. Alternatively, you can prune the fields to a subset by default. The <JSON> looks like `{ foo=true, bar={baz=true}, bap=true} ` to imply the endpoint should send down field `foo`, nested object `bar` with only its field `baz` and the entire default nested object `bap`. I achieve this in Django Rest Framework by using meta-classes.