gistfile1.txt

var restify = require('restify');
var server = restify.createServer({ name: 'example' });
var fs = require('fs');

server.listen(8080, function () {
  console.log('%s listening at %s', server.name, server.url);
});

server.use(restify.fullResponse()).use(restify.bodyParser());

server.post('/api/signature', function (req, res, next) {
  fs.writeFileSync("img.png", new Buffer(req.body, 'base64'));
  res.send(200);
});