tasks/options/express-server.js
```javascript
module.exports = {
	options: {
		APIMethod: "<%= package.APIMethod %>",		// stub or proxy
		proxyURL: "<%= package.proxyURL %>",			// URL to the API server, if using APIMethod: 'proxy'
		rewriteNamespace: ''
	}
};
```
tasks/express-server.js
```javascript
      var rewriteNamespace = grunt.config('express-server.options.rewriteNamespace');
      
      grunt.log.writeln('Proxying API requests to: ' + proxyURL);

      // Use API proxy
      app.all('/api/*', passThrough(proxyURL, rewriteNamespace));

// ....

  function passThrough(target, namespace) {
    return function(req, res) {
      var url = req.url.replace('/api', namespace);

      req.pipe(request(target+url)).pipe(res);
    };
  }
```