browsersync api post .

browsersync.conf

middleware: [
    {
        route: "/api",
        handle: function (req, res, next) {
            
            var url = req.url;

            var filename = __dirname + '/api' + url;

            if (url.indexOf('.json') > -1 && fs.existsSync(filename)) {

              var contents = fs.readFileSync(filename, {
                encoding: 'utf8'
              });

              res.end(contents);

            } else {
              next();
            }
        }
      }
    ]