> 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/external-events/monitoring-tools.md).

# Monitoring Tools

Guardian's monitoring tools provide infrastructure for external systems to observe and react to Guardian's internal event stream without requiring a direct NATS connection.

## Application Events Module

The [Application Events Module](/guardian/standard-registry/external-events/monitoring-tools/application-events-module.md) is a standalone HTTP service (port `3012`) that:

* Subscribes to all Guardian NATS event subjects on startup
* Exposes a REST API for registering and managing webhooks
* Delivers events to registered webhook URLs via HTTP POST
* Provides a streaming JSON endpoint for real-time event consumption

| Capability                        | Endpoint                    |
| --------------------------------- | --------------------------- |
| Register a webhook                | `POST /api/webhooks`        |
| List registered webhooks          | `GET /api/webhooks`         |
| Retrieve a single webhook         | `GET /api/webhooks/{id}`    |
| Update a webhook                  | `PUT /api/webhooks/{id}`    |
| Delete a webhook                  | `DELETE /api/webhooks/{id}` |
| List all available event subjects | `GET /api/events`           |
| Subscribe to live event stream    | `GET /api/events/subscribe` |
| Interactive API documentation     | `GET /api-docs`             |

For full details see [Application Events Module](/guardian/standard-registry/external-events/monitoring-tools/application-events-module.md).