Really helpful tutorial! Thanks a lot!
but I got only one question,
I made this request:
http://myWebSite.com/wp-json/wp/v2/posts/?meta_key=views&orderby=meta_value_num

And I got this response:

{"code":"rest_invalid_param","message":"Invalid parameter(s): orderby","data":{"status":400,"params":{"orderby":"orderby is not one of author, date, id, include, modified, parent, relevance, slug, title."}}}

Can you please help me where my mistake is ?