# Interface.deprecated

URL: /business/events/Interface.deprecated · Id: `event:Interface.deprecated`

> Emitted each time an Interface is deprecated.

[Interface.deprecate](/business/nouns/interface/deprecate) emits `Interface.deprecated` when it completes on an [Interface](/business/nouns/interface).

| Property | Value |
| --- | --- |
| Emitted by | [Interface.deprecate](/business/nouns/interface/deprecate) |
| Noun | [Interface](/business/nouns/interface) |
| Wakes | None. |

### Payload
Each delivery is an [Event](/business/nouns/event) record. `data` holds what [Interface.deprecate](/business/nouns/interface/deprecate) returns.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `name` | `string` | Yes | `Interface.deprecated`. |
| `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.interface` | [Interface](/business/nouns/interface) | Yes | The API, with the version deprecated. |
| `data.interface.kind` | `string` | Yes | One of `api`, `cli`, `mcp`, `sdk`, `site`, `app`, `docs`, or `webhooks`. |
| `data.interface.path` | `string` | No | Where it is mounted on its Domain, such as `/api`. |
| `data.interface.conformsTo` | `json` | No | The Standards it also speaks, each mapping the Standard’s operations onto the Product’s Verbs. |

### Example
```json
{
  "$id": "https://api.sb/leaseline.app/events/evt_8zf0ubvbmR",
  "$type": "Event",
  "name": "Interface.deprecated",
  "at": "2026-10-22T12:00:00Z",
  "data": {
    "interface": {
      "$id": "https://api.sb/leaseline.app/interfaces/interface_TMyQ3kh9uX",
      "$type": "Interface",
      "kind": "api",
      "path": "/",
      "conformsTo": {
        "standard": "openai-chat",
        "operations": {
          "chat.completions.create": "Listing.write"
        }
      }
    }
  },
  "seq": 2379
}
```