var settings = {
  "async": true,
  "crossDomain": true,
  "url": "http://mockbin.com/har",
  "method": "POST",
  "headers": {
    "content-type": "application/json"
  },
  "processData": false,
  "data": "{\"number\":1,\"string\":\"f\\\"oo\",\"arr\":[1,2,3],\"nested\":{\"a\":\"b\"},\"arr_mix\":[1,\"a\",{\"arr_mix_nested\":{}}],\"boolean\":false}"
}

$.ajax(settings).done(function (response) {
  console.log(response);
});
