# trigger

> Talos 0.6 · Since 0.6

Use it in a scene entity's `components` list as `{ "type": "trigger", … }`. The contract writes the fields flat and refuses unknown keys.

## Fields

| Field | Type | Required | Default | Allowed values | Description |
|---|---|---|---|---|---|
| `event` | `string` | yes |  |  |  |
| `once` | `boolean` | no |  |  |  |

## Rules that can refuse it

- `dynamic-needs-collider`
- `missing-collider`
- `play/interaction-unreached`
- `play/trigger-noop`
- `trigger-needs-trigger-collider`
- `vehicle-needs-dynamic-body`

## Example

From the contract's tested fixture `fixtures/contract/full20/scene.json#hazard-zone`.

```json
{
  "type": "trigger",
  "event": "hazard-reached",
  "once": true
}
```