A polymer 2 component using iron-ajax to load some data

polymer-playground-app.html

<link rel="import" href="../../bower_components/polymer/polymer-element.html">
<link rel="import" href="../../bower_components/iron-ajax/iron-ajax.html">

<dom-module id="polymer-playground-app">
  <template>
    <iron-ajax auto url="https://jsonplaceholder.typicode.com/posts/1" handle-as="json" last-response="{{post}}"></iron-ajax>
    <p>[[post.title]]</p>
  </template>

  <script>
    /**
     * @customElement
     * @polymer
     */
    class PolymerPlaygroundApp extends Polymer.Element {
      static get is() { return 'polymer-playground-app'; }
      static get properties() {
        return {
          post: {
            type: Object
          }
        };
      }
    }

    window.customElements.define(PolymerPlaygroundApp.is, PolymerPlaygroundApp);
  </script>
</dom-module>