There is a HTTP plugin for MySQL available at labs.mysql.com. Ulf Wendel covers it in more detail.
The development preview brings three APIs: key-document for nested JSON documents, CRUD for JSON mapped SQL tables and plain SQL with JSON replies. More so: MySQL 5.7.4 has SQL functions for modifying JSON, for searching documents and new indexing methods!
At this point I still have more questions than answers, but I’m definitely intrigued.