# Set an application API grant

`PUT /v1/applications/{application_id}/api-grants/{api_id}` · permission `applications:write`

Replaces, as a whole, the scopes an application may request for one API. An application can hold grants for at most 50 APIs.

## Request

| Parameter | In | Description |
|---|---|---|
| `application_id` | path | Application id (`app_…`). |
| `api_id` | path | API id (`api_…`). |

**Body**

| Field | Type | Required | Description |
|---|---|---|---|
| `scopes` | string[] | yes | Allowed scopes (`resource:action`); each must be defined on the API. At most 1000. |
| `default_scopes` | string[] | no | Scopes granted by default; a subset of `scopes`. |

## Response

`200 OK` with the grant.

```json
{
  "application_id": "app_6f8d0cjgbmf0gtn2rg6pscp3cg",
  "api_id": "api_0000000000000000000000001z",
  "scopes": ["orders:read", "orders:write"],
  "default_scopes": ["orders:read"],
  "created_at": "2026-10-05T10:00:01Z",
  "updated_at": "2026-10-05T10:00:01Z"
}
```

## Errors

| HTTP | `code` | When |
|---|---|---|
| 401 | `unauthenticated` | The key is missing, invalid or revoked. |
| 403 | `insufficient_permissions` | The key lacks the required permission. |
| 404 | `not_found` | The application or the grant does not exist in this environment. |
| 422 | `validation_failed` | A scope is malformed or not defined on the API, or `default_scopes` is not a subset of `scopes`. |
| 403 | `quota_exceeded` | The application already holds grants for 50 APIs. |
| 400 | `unknown_field` | The body has a field that is not part of the schema. |

## Example

```bash
curl -X PUT https://api.eu.keenauth.com/v1/applications/app_6f8d0cjgbmf0gtn2rg6pscp3cg/api-grants/api_0000000000000000000000001z \
  -H "Authorization: Bearer $KEENAUTH_SECRET_KEY" \
  -H "Content-Type: application/json" \
  -d '{"scopes":["orders:read","orders:write"],"default_scopes":["orders:read"]}'
```