Events

An event is a typed fact sent into a workflow run. The workflow waits; a product API sends the payload with a deduplication key.

final receipt = await flow.waitForEvent(
  paymentReceived,
  id: 'payment',
);

Events sent before the workflow waits are buffered. Duplicate deliveries with the same idempotency key do not append a second history event.

JSON documents use an event step and an inputBinding for the expected payload shape.

When to Use an Event vs Work

Use	Why
Work	An actor is asked to do something and must respond
Event	A system, webhook, or another execution path reports a fact

Do not hide automated execution inside a work response handler. Start the external job in an operation, then wait for an event.

See Also

• Event delivery
• Service API