http://developer.teradata.com/blog/jasonstrimpel/2011/11/backbone-js-and-socket-io

backbone.socket.io.sync.coffee

Backbone.sync = (method, model, options = null)->
  socket = window.NAMESPACE.socket
  @signature = (model)->
    sig = {}
    sig.endPoint = model.url + (('/' + model.id) if model.id else '')
    sig.ctx = model.ctx if model.ctx
    sig

  @event = (operation, sig)->
    if sig.ctx 
      "#{operation}:#{sig.endPoint}:#{sig.ctx}"
    else 
      "#{operation}:#{sig.endPoint}"

  @create = (model)->
    sign = signature model
    e = event 'create', sign
    socket.emit 'create', 
      'signature' : sign
      item : model.attributes
    socket.once e, (data)->
      model.id = data.id
    console.log model
 
  switch method
    when 'create'
      @create model
    when 'read'
      @read model
    when 'update'
      @update model
    when 'delete'
      @destroy model
#WIP

backbone.socket.io.sync.js

Backbone.sync = function (method, model, options) {
    var socket = window.NAMESPACE.socket; // grab active socket from global namespace; io.connect() was used to create socket
 
    /*
     * Create signature object that will emitted to server with every request. 
     * This is used on the server to push an event back to the client listener.
     */
    var signature = function (model) {
        var sig = {};    
         
        sig.endPoint = model.url + (model.id ? ('/' + model.id) : '');
        if (model.ctx) sig.ctx = model.ctx;
 
        return sig;
    };
     
    /*
     * Create an event listener for server push. The server notifies
     * the client upon success of CRUD operation.
     */
    var event = function (operation, sig) {
        var e = operation + ':'; 
        e += sig.endPoint;
        if (sig.ctx) e += (':' + sig.ctx);
 
        return e;
    };
     
    // Save a new model to the server.
    var create = function (model) {  
        var sign = signature(model); 
        var e = event('create', sign);
        socket.emit('create', {'signature' : sign, item : model.attributes }); 
        socket.once(e, function (data) {
            model.id = data.id;  
            console.log(model);                     
        });                           
    };              
 
    // Get a collection or model from the server.
    var read = function (model) {
        var sign = signature(model);
        var e = event('read', sign);
        socket.emit('read', {'signature' : sign});  
        socket.once(e, function (data) {
            options.success(data); // updates collection, model; fetch                      
        });   
    }; 
     
    // Save an existing model to the server.
    var update = function (model) {
        var sign = signature(model); 
        var e = event('update', sign);
        socket.emit('update', {'signature' : sign, item : model.attributes }); // model.attribues is the model data
        socket.once(e, function (data) { 
            console.log(data);                     
        });                           
    };  
     
    // Delete a model on the server.
    var destroy = function (model) {
        var sign = signature(model); 
        var e = event('delete', sign);
        socket.emit('delete', {'signature' : sign, item : model.attributes }); // model.attribues is the model data
        socket.once(e, function (data) { 
            console.log(data);                     
        });                           
    };             
       
    // entry point for method
    switch (method) {
        case 'create':
            create(model);
            break;        
        case 'read':  
            read(model); 
            break;  
        case 'update':
            update(model);
            break;
        case 'delete':
            destroy(model);
            break; 
    }        
};

socket.io.stub.js

/*
 * This is a stub for a socket.io server that responds to CRUD operations
 */
var io = require('socket.io').listen(3000);
 
var create = function (socket, signature) {
    var data = [];
    var e = event('create', signature);
    socket.emit(e, {id : 1});           
};
 
var read = function (socket, signature) {
    var data = [];
    var e = event('read', signature);
    data.push({})
    socket.emit(e, data);           
};
 
var update = function (socket, signature) {
    var data = [];
    var e = event('update', signature);
    socket.emit(e, {success : true});           
};
 
var destroy = function (socket, signature) {
    var data = [];
    var e = event('delete', signature);
    socket.emit(e, {success : true});           
};
 
// creates the event to push to listening clients
var event = function (operation, sig) {
    var e = operation + ':';
    e += sig.endPoint;
    if (sig.ctx) e += (':' + sig.ctx);
 
    return e;
};
 
io.sockets.on('connection', function (socket) {
    socket.on('create', function (data) {
        create(socket, data.signature);      
    });     
    socket.on('read', function (data) {
        read(socket, data.signature);
    }); 
    socket.on('update', function (data) {
        update(socket, data.signature);      
    });
    socket.on('delete', function (data) {
        destroy(socket, data.signature);      
    });               
});

The more I read it, the more I find errors, correction incoming today !