<div id="root">
  <p>Selected tab is {{active}}</p>
  <amber-tabs
    v-on:change="updateData"
    v-bind:active="active"
    labels="One, Two"
  ></amber-tabs>
</div>

const app = new Vue({
  el: '#root',
  data: {
    active: 0
  },
  methods: {
    updateData: function(evt) {
      this.active = evt.detail.active;
    } 
  }
});