# Dataset.backfilled

URL: /business/events/Dataset.backfilled · Id: `event:Dataset.backfilled`

> Emitted each time a Dataset is backfilled.

[Dataset.backfill](/business/nouns/dataset/backfill) emits `Dataset.backfilled` when it completes on a [Dataset](/business/nouns/dataset).

| Property | Value |
| --- | --- |
| Emitted by | [Dataset.backfill](/business/nouns/dataset/backfill) |
| Noun | [Dataset](/business/nouns/dataset) |
| Wakes | None. |

### Payload
Each delivery is an [Event](/business/nouns/event) record. `data` holds what [Dataset.backfill](/business/nouns/dataset/backfill) returns.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `name` | `string` | Yes | `Dataset.backfilled`. |
| `at` | `datetime` | Yes | When it happened. |
| `seq` | `integer` | No | Its position in the namespace, one more than the Event before; any seq is a cursor into the history. |
| `data` | `json` | Yes | The Thing as the Action left it. |
| `data.dataset` | [Dataset](/business/nouns/dataset) | Yes | The Dataset, with the range filled. |
| `data.dataset.name` | `string` | Yes | The name of the Product. |
| `data.dataset.promise` | `text` | Yes | What the Customer can rely on. |
| `data.dataset.status` | `string` | Yes | One of `draft`, `selling` or `retired`, set by its Offers. |
| `data.dataset.records` | `integer` | No | How many Things it holds. |
| `data.dataset.refreshedAt` | `datetime` | No | When its Sources were last read. |

### Example
```json
{
  "$id": "https://api.sb/ratebook.dev/events/evt_RbgZfktXTI",
  "$type": "Event",
  "name": "Dataset.backfilled",
  "at": "2026-10-22T12:00:00Z",
  "data": {
    "dataset": {
      "$id": "https://api.sb/ratebook.dev/datasets/dataset_UDQXk0KsJB",
      "$type": "Dataset",
      "name": "Ratebook",
      "promise": "A rate for any US address in under 100 milliseconds.",
      "status": "draft",
      "records": 1,
      "refreshedAt": "2026-10-22T12:00:00Z"
    }
  },
  "seq": 2664
}
```