Nginx和AJAX否认

Question

How can I denny users from accessing some url in my site but allow an ajax service to access it. I was thinking to do something like this in NGINX:

/location something.html {
 allow 127.0.0.1;
 deny all;
}

So anyone who tries to enter mydomain.com/something.html from the browser with any IP gets a 403 but the ajax call that is running from localhost can access the url.

Although this is not working.

Any ideas how to achieve this?