code: function handler(req, res) {
  
          var path = cog.getConfig('options.api_data');
          var urlRegex = cog.getConfig('options.api_url_regex');
          var url = req.url.replace(/^\//, '').replace(/\/$/, '');
  
          console.log(req.method + ' ' + req.url);
  
          // Find the JSON-data file and serve it, if URL points to the API.
          if (path && urlRegex && urlRegex.test(url)) {
              var file = path + '/' + url + '.json';
              if (grunt.file.exists(file)) {
                  res.end(grunt.file.read(file));
                  return;
              }
          }
  
          if (req.method == 'POST') {
              // TODO: This needs fixing, since it throws an error.
              res.end('{"message": "OK"}');
          }
  
      }
docs: This is the development server used by CoG.