Stately
XState v6 alpha

Inspection

Observe actor systems and transitions.

Pass an inspector to the root actor with the inspect option.

const actor = createActor(machine, {
  inspect: (inspectionEvent) => {
    console.log(inspectionEvent.type, inspectionEvent);
  }
});

Inspection emits two event types:

TypeContains
@xstate.actorActor identity and parent information.
@xstate.transitionThe event, snapshot, source, target and microsteps.

Use inspection for developer tools, logs and visualizers. Do not change application state from an inspector.

Inspection can power a statechart visualizer or attach actor and transition details to a failed request trace.

Inspection cheatsheet

createActor(logic, { inspect });
createActor(logic, { inspect: (event) => console.log(event) });

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