Tags

State nodes can have tags, which are string terms that help group or categorize the state node. For example, you can signify which state nodes represent states in which data is being loaded by using a "loading" tag, and determine if a state contains those tagged state nodes with state.hasTag(tag):

const feedbackMachine = createMachine({
  id: 'feedback',
  initial: 'prompt',
  states: {
    prompt: {
      tags: ['visible'],
      // ...
    },
    form: {
      tags: ['visible'],
      // ...
    },
    thanks: {
      tags: ['visible', 'confetti'],
      // ...
    },
    closed: {
      tags: ['hidden'],
    },
  },
});

const feedbackActor = createActor(feedbackMachine).start();

console.log(feedbackActor..getSnapshot().hasTag('visible'));
// logs true

Tags and TypeScript

XState v5 requires TypeScript version 5.0 or greater.

For best results, use the latest TypeScript version. Read more about XState and TypeScript

You can strongly type the tags of your machine in the types.tags property of the machine config.

const machine = createMachine({
  types: {} as {
    tags: 'pending' | 'success' | 'error';
  },
  // ...
  states: {
    loadingUser: {
      tags: ['pending'],
    },
  },
});

const actor = createActor(machine).start();

actor
  .getSnapshot()
  // Autocompleted
  .hasTag('pending');