> For the complete documentation index, see [llms.txt](https://docs.n8n.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.n8n.io/deploy/host-n8n/configure-n8n/basic-configuration/use-environment-variables/external-hooks.md).

# External hooks

{% hint style="info" %}
**File-based configuration**

You can add `_FILE` to individual variables to provide their configuration in a separate file. Refer to [Keeping sensitive data in separate files](/deploy/host-n8n/configure-n8n/basic-configuration.md#keeping-sensitive-data-in-separate-files) for more details.
{% endhint %}

You can define external hooks that n8n executes whenever a specific operation runs. Refer to [External hooks](/deploy/host-n8n/configure-n8n/external-hooks.md) for the full reference, including available hooks and file formatting.

| Variable                        | Type   | Default | Description                                                                                                                            |
| ------------------------------- | ------ | ------- | -------------------------------------------------------------------------------------------------------------------------------------- |
| `EXTERNAL_HOOK_FILES`           | String | -       | Files containing backend external hooks. Provide multiple files separated by the character defined in `EXTERNAL_HOOK_FILES_SEPARATOR`. |
| `EXTERNAL_HOOK_FILES_SEPARATOR` | String | `:`     | Separator character for `EXTERNAL_HOOK_FILES`. Use `;` on Windows to avoid conflicts with drive-letter paths like `C:\`.               |
| `EXTERNAL_FRONTEND_HOOKS_URLS`  | String | -       | URLs to files containing frontend external hooks. Provide multiple URLs as a colon-separated list ("`:`").                             |