Very basic modification of Express JS res.json(). Adds the safety prefix for Angular JS to the body of all json responses. Extends the response object with one method: ngJSON. Simply require file somewhere in application (normally app.js) before executing ngJSON responses.

ngjson.js

var http = require('http');

var NG_PREFIX = ")]}',\n";

http.ServerResponse.prototype.ngJSON = function(obj){
    // allow status / body
    if (2 == arguments.length) {
      // res.json(body, status) backwards compat
      if ('number' == typeof arguments[1]) {
        this.statusCode = arguments[1];
      } else {
        this.statusCode = obj;
        obj = arguments[1];
      }
    }

    // settings
    var app = this.app;
    var replacer = app.get('json replacer');
    var spaces = app.get('json spaces');
    var body = JSON.stringify(obj, replacer, spaces);

    // content-type
    this.get('Content-Type') || this.set('Content-Type', 'application/json');

    return this.send(NG_PREFIX + body);
};

//e.x. res.ngJSON({ name : 'Tyler' });
//e.x. res.ngJSON(500, { error : 'Something something dark side' });