The bare minimum you must do to get Backbone.js Models to work with CouchDB.

backbone-models-for-couchdb-boiler-plate.js

var SomeModelClass = Backbone.Model.extend({

  idAttribute: "_id",

  url: function() {
    if (_.has(this, 'id')) {
      var url = (_.has(this.toJSON(), '_rev'))
        ? this.server + '/' + this.db + '/' + this.id + '?rev=' + this.get('_rev') // For UPDATE and DELETE
        : this.server + '/' + this.db + '/' + this.id // For READ
    }
    else {
      var url = this.server + '/' + this.db // for CREATE
    }
    return url
  },
  
  // Set your server. For example, http://127.0.0.1:5984
  server: null,

  // Set your database.  In web browsers, to use the current database in browser's URL, use document.URL.split("/")[3]
  db : null,
  
})

var someModel = new SomeModelClass({db: "someDatabase", server: "http://127.0.0.1:5984"})