The furnace.auth.providers.couchdb vocabulary implements an authentication provider which looks up authentication requests in a CouchDB. It is necessary to create a view associating usernames with user documents before using this vocabulary; see documentation for couchdb-auth-provider.

Although this implementation guarantees that users with duplicate IDs/emails cannot be created in a single CouchDB database, it provides so such guarentee if you are clustering multiple DBs. In this case, you are responsible for ensuring the uniqueness of users across databases.

Password hashes are base64 encoded.