Question: I have many of these "controllers": 

```
app.get('/',function(req,res){
    var stuff = { 'title': 'blah' };
    res.render('mytemplate',stuff);
});    

```

Notice res.render? I want to add this header to every response header I make:

`X-XSS-Protection: 0`

How can I add that response header automatically?

Answer: 
```
// global controller
app.get('/*',function(req,res,next){
    res.header('X-XSS-Protection' , 0 );
    next(); // http://expressjs.com/guide.html#passing-route control
});

```

Just make sure this is the first controller you add, order is significant.
For express 4.x, the idiomatic way is as follows:

### Implementation

```
// no mount path; executed for every request.
app.use(function (req, res, next) {
  res.set('X-XSS-Protection', 0);
  next();
});

```

### Test

```
describe('Response Headers', function () {
  it('responds with header X-XSS-Protection: 0', function (done) {
    hippie(app)
    .get('/any/route/you/can/think/of')
    .expectHeader('X-XSS-Protection', 0)
    .end(done);
  });
});

```

### Dev Dependencies (for tests to work)

```
% npm install --save-dev mocha hippie

```

### Relevant Documentation

* [Application Level Middleware](http://expressjs.com/guide/using-middleware.html#middleware.application)
* [res.set](http://expressjs.com/4x/api.html#res.set)