How to use async data in metaInfo?

vue-meta will do this for you automatically when your component state changes.

Just make sure that you're using the function form of metaInfo:

{
  data () {
    return {
      title: 'Foo Bar Baz'
    }
  },
  metaInfo () {
    return {
      title: this.title
    }
  }
}

Check out the vuex-async example for a more detailed demonstration