# Validate Response Links
URL: /reference/blocks/automation-validate-response-links
Type: reference
Description: Check that all URLs in a response are from allowed KB sources
Keywords: validate response links, automation/validate-response-links, system, automation, block, workflow builder
`automation/validate-response-links` — Check that all URLs in a response are from allowed KB sources.

Where it appears [#where-it-appears]

The **Validate Response Links** block lives in the **Logic & control** group of the Workflow Builder.

Fields [#fields]

| Field         | Type                                   | Required | Default | Description                                                                                                                                         |
| ------------- | -------------------------------------- | -------- | ------- | --------------------------------------------------------------------------------------------------------------------------------------------------- |
| `response`    | text (multi-line, supports references) | Yes      | —       | The response text whose URLs should be validated against the allowed sources. Use literal text or \<StepName.field> to reference a generated reply. |
| `allowedUrls` | code                                   | Yes      | —       | JSON array of allowed base URLs/sources; any link in the response not matching one of these is flagged as invalid.                                  |

Inputs and outputs [#inputs-and-outputs]

Inputs are the configurable fields above. The block produces these outputs:

**Outputs**

Reference an output downstream with `<Validate Response Links.field>`.

| Name          | Type    | Description                 |
| ------------- | ------- | --------------------------- |
| `success`     | boolean | Success status              |
| `isValid`     | boolean | Whether all links are valid |
| `invalidUrls` | array   | Invalid URLs found          |
| `error`       | string  | Error message if failed     |

Example [#example]

A minimal configuration for this block:

```json
{
  "type": "automation/validate-response-links",
  "config": {
    "response": "<PreviousStep.field>",
    "allowedUrls": "..."
  }
}
```

Limits and failure modes [#limits-and-failure-modes]

* Required fields (`response`, `allowedUrls`) must be set, or the block fails validation before it runs.
* On failure the `error` output is populated; downstream blocks that reference other outputs may not receive values.

Related [#related]

* [All workflow blocks](/reference/blocks)
* [Workflow Builder overview](/workflow-builder-overview)