> For the complete documentation index, see [llms.txt](https://dev.guardian.hedera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev.guardian.hedera.com/guardian/standard-registry/policies/tools/tools-apis/run-policy-without-making-any-persistent-changes-or-executing-transaction..md).

# Run policy without making any persistent changes or executing transaction.

**`PUT /api/v1/tools/{id}/dry-run`**

Runs a tool without making any persistent changes or executing transactions, allowing safe testing of the tool configuration.

**Authentication:** Bearer token required (`Authorization: Bearer <token>`)

**Permission:** `Permissions.TOOLS_TOOL_UPDATE`

***

## Request

### Path Parameters

| Parameter | Type   | Required | Description                |
| --------- | ------ | -------- | -------------------------- |
| `id`      | string | Yes      | Tool ID (MongoDB ObjectId) |

***

## Response

### Success Response

**Status:** `200 OK`

```json
{
  "valid": true,
  "results": []
}
```

### Error Responses

| Status                      | Description                |
| --------------------------- | -------------------------- |
| `401 Unauthorized`          | Missing or invalid token   |
| `403 Forbidden`             | Insufficient permissions   |
| `422 Unprocessable Entity`  | `id` is missing or invalid |
| `500 Internal Server Error` | Unexpected server failure  |