# Replace the application theme

`PUT /v1/branding/applications/{application_id}` · permission `branding:write`

Replaces the whole theme draft of the scope; tokens missing from the body are cleared. `{"theme":{}}` clears the scope. `If-Match` carries this scope's `ETag` (from the matching GET), not the environment's.

## Request

| Field | Type | Required | Description |
|---|---|---|---|
| `application_id` | path | yes | `app_…` id. |
| `If-Match` | header | yes | The `ETag` of the draft as last read (`"0"` if never written). Missing: `428`; stale: `412`. |
| `theme` | object | yes | Full `BrandingTheme` of the scope. |

## Response

`200 OK` with the scope's theme draft and its `ETag` (each scope has its own version).

```json
{
  "theme": {"logo": "logo_acme", "light": {"color": {"primary": "#0a3d91"}}},
  "updated_at": "2026-10-05T09:30:00.123456Z"
}
```

## Errors

| HTTP | code | When |
|---|---|---|
| 400 | `unknown_field` | The body has an unknown field or is not a JSON object. |
| 404 | `not_found` | The application does not exist in this environment, or the id is malformed. |
| 412 | `precondition_failed` | `If-Match` does not match the current version of the draft. |
| 422 | `validation_failed` | A token value is invalid (`invalid_value`, `out_of_range`, `unknown_token`); `pointer` names the token, e.g. `/theme/light/color/primary`. |
| 428 | `precondition_required` | The `If-Match` header is missing. |
| 401 | `unauthenticated` | The credential is missing, invalid or revoked. |
| 403 | `insufficient_permissions` | The credential lacks the required permission. |
| 429 | `rate_limited` | The rate limit was exceeded; retry after the `Retry-After` period. |
| 503 | `service_unavailable` | A dependency is temporarily unavailable; retry after the `Retry-After` period. |

## Example

```bash
curl -X PUT https://api.eu.keenauth.com/v1/branding/applications/app_01jbexample0000000000000000 \
  -H "Authorization: Bearer $KEENAUTH_SECRET_KEY" \
  -H "Content-Type: application/json" \
  -H 'If-Match: "1"' \
  -d '{"theme":{"logo":"logo_acme","light":{"color":{"primary":"#0a3d91"}}}}'
```