A node script than opens a server and creates a bash script per each request, containing the curl command to replicate the request it received.

request-to-curl.js

#!/usr/bin/env node

//jshint node:true
'use strict';
var fs = require('fs');
var url = require('url');
var http = require('http');

var port = process.argv[2];
var folder = process.argv[3];
var counts = {};
folder = folder ? folder + '/' : '';

if (!port) {
  console.error('Usage: ', process.argv[1], 'port:Number folder:Optional');
  process.exit(1);
}


if (folder && !fs.existsSync(folder))
  fs.mkdirSync(folder);

function getFilename(path) {
  counts[path] = counts[path] || 0;
  var number = counts[path]++;
  var parsed = url.parse(path);
  var cleaned = parsed.pathname
    .replace(/\//g, '_')
    .replace(/^_|_$/g, '');
  var filename = cleaned + '.' + number + '.sh'
  return folder + filename;
}

function end(response) {
  response.writeHead(200, {
    'Access-Control-Allow-Origin': '*',
    'Access-Control-Allow-Headers': 'Origin, X-Requested-With, Content-Type, Accept',
  });
  response.end();
}

function escape(text) {
  return '\'' + text.replace(/'/g, '\'"\'"\'') + '\'';
}

http.createServer(function(request, response) {
  if (request.method === 'OPTIONS')
    return end(response);

  var data = '';
  request.on('data', function(chunk) { data += chunk });

  request.on('end', function() {
    var script = [ '#/bin/bash\n\ncurl', '-X', request.method ];

    // headers
    Object.keys(request.headers).forEach(function(header) {
      script.push('\\\n\t-H', escape(header + ': ' + request.headers[header]));
    });

    // request body
    script.push('\\\n\t-d', escape(data));

    // url
    script.push('\\\n\t' + escape('http://localhost:' + port + request.url));

    // save
    var filename = getFilename(request.url);
    console.log('Saving', filename);
    fs.writeFile(filename, script.join(' '));
    end(response);
  });

}).listen(port);

console.log('Listening at port', port);