Events

An event is the atomic unit of data that moves through a Pipeline. Every record a source connector emits, every row a transform produces, and every write a destination connector performs is an event.

Event shape

{
  "id": "evt_8f2c1a90",
  "type": "order.created",
  "occurred_at": "2026-08-18T09:12:44Z",
  "source": "connector_postgres_orders",
  "payload": { "order_id": "ord_4471", "amount_cents": 4899 }
}

User data events vs. platform events

KMP distinguishes two kinds of events:

User data events — the records your pipelines process, shaped however your source system produces them.
Platform events — lifecycle notifications KMP itself emits: pipeline.started, pipeline.completed, pipeline.failed, connector.error. These are what power Webhooks.

Ordering

Events are delivered in-order per source partition, not globally. Two events from different source partitions may be processed out of order relative to each other.

Retries and dead-lettering

An event that fails a transform or destination write is retried with exponential backoff. After the configured retry limit, it is moved to that pipeline's dead-letter queue rather than dropped. See Handling errors & retries for how to configure and drain a dead-letter queue.