---
title: 'Emit Event'
description: 'Raise a new OneHazel event that can trigger another workflow.'
---
# Emit Event

Publishes a new event into OneHazel's event stream. Any other workflow whose
Event Trigger matches the emitted `eventType` will fire when this runs.

## When to use

- You want one workflow to trigger another without coupling them directly.
- You want to fan-out a single inbound event into multiple downstream
  workflows (one Event Trigger per consumer).
- Emitting custom business events for analytics or audit.

## Configuration

| Field | Required | What it does |
|---|---|---|
| `eventType` | Yes | The event type string downstream triggers will match on. |
| `payload` | No | JSON object carrying the event data. Supports `{{...}}` refs. |

## What it outputs

```
{
  eventId: "evt_...",
  eventType: "...",
  emitted: true
}
```

The emitted event is also persisted in the `events` table and is visible
in the admin event viewer for auditing.

## Gotchas

- Emitted events are processed by the workflow engine asynchronously.
  Downstream workflows may fire within a few seconds, not synchronously
  with this node's completion. If you need synchronous behaviour, have
  this workflow do the work directly.
- **No dedup**: emitting the same `eventType` + payload twice fires
  downstream workflows twice. If you need exactly-once semantics, add an
  idempotency key to the payload and check it in the downstream workflow.