I am using mongoose (node), what is the best way to output id instead of _id?
I create a toClient() method on my models where I do this. It's also a good place to rename/remove other attributes you don't want to send to the client:
Schema.method('toClient', function() {
var obj = this.toObject();
//Rename fields
obj.id = obj._id;
delete obj._id;
return obj;
});