# GET / PATCH /v1/projects/:projectId/ads/:platform/defaults (/docs/api/reference/ads/patch-defaults)



<Endpoint method="GET" path="/v1/projects/:projectId/ads/{platform}/defaults" scope="ads:read" phase="1" />

<Endpoint method="PATCH" path="/v1/projects/:projectId/ads/{platform}/defaults" scope="ads:write:policy" phase="1" />

The defaults block is the layer-level authority fallback — campaigns without a per-campaign authority pin inherit from here. Per-campaign authority overrides defaults.

PATCH from a partner key is gated by the customer's policy. With `layer:write` scope per the parity flavor (LOCK 1), partners can adjust defaults, though some customers configure their layer to refuse partner-issued defaults changes.

## GET response [#get-response]

```json
{
  "layerId": "lyr_8b3c1d2e-4f5a-46b7-9c8d-0e1f2a3b4c5d",
  "platform": "meta",
  "defaults": {
    "creative": "auto",
    "tactical": "draft",
    "structural": "off"
  },
  "killSwitchActive": false,
  "lastModifiedAt": "2026-05-08T14:32:11Z",
  "lastModifiedBy": {
    "actorType": "user",
    "actorOrganizationId": "org_2481fa5c..."
  }
}
```

`killSwitchActive` — if `true`, every write to the layer is denied regardless of axis state. The kill switch is **customer-only writable**; partners cannot trip or release it. Partners observe it here passively.

## PATCH body [#patch-body]

<Parameters
  title="Body"
  rows="[
  { name: 'defaults', type: 'object', required: true, description: '`{ creative?, tactical?, structural? }`. Partial updates allowed.' },
]"
/>

## Errors [#errors]

| Code               | When                                                             |
| ------------------ | ---------------------------------------------------------------- |
| `AUTHORITY_DENIED` | Customer's layer policy refuses partner-issued defaults changes. |
| `FORBIDDEN_SCOPE`  | Key lacks `ads:write:policy`.                                    |

## See also [#see-also]

* [Ads write model](/docs/api/concepts/ads-write-model)
* [`PATCH …/campaigns/:id/authority`](/docs/api/reference/ads/patch-campaign-authority)