There are a variety of libraries that can make our lives easier when developing with PHP and CouchDB. All of the libraries are open source projects, which is great! But, some of these libraries have not been actively worked on to support the newer versions of CouchDB. Therefore, we will need to be selective with the libraries we choose to work with.
A list of some of the PHP and CouchDB libraries can be seen here: http://wiki.apache.org/couchdb/Getting_started_with_PHP, and there are a variety of others hosted on GitHub that require a bit more digging.
Each library has strengths, but because simplicity is the key concept of Bones, it makes sense that we should also strive for simplicity in our PHP library. With that being said, our best solution is called Sag.