> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cedarai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Train Departure Webhook

> Event payload sent when a train departs from a station

## Event Overview

The **Train Departure** webhook fires when a train departs from a station, customer location, or serving location in your network. It delivers equipment details, the departure station, customer and serving location (when applicable), loaded/empty status, the train number, and the associated work order (if any).

This webhook supports the "early departure" scenario where a train leaves directly from a customer location rather than the main yard. In that case, `customer_location` and `serving_location` are populated so your integration can distinguish between a normal yard departure and a customer-site departure.

<Info>
  This webhook is triggered through ARMS workflow automation. Configure it in your workflow rules to notify external
  systems when trains depart from specific locations.
</Info>

***

## Payload Schema

```json theme={null}
{
  "event_type": "TrainDeparture",
  "event_timestamp": "2026-06-17T09:30:00+00:00",
  "work_order_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "linked_resources": {
    "equipment": [
      {
        "resource_id": 100001,
        "car_number": "GCGO 995823",
        "is_loaded": true
      },
      {
        "resource_id": 100002,
        "car_number": "GCGO 726451",
        "is_loaded": false
      }
    ],
    "event_station": {
      "resource_id": 1001,
      "name": "Göteborg Hamn",
      "grouping_type": "station"
    },
    "customer_location": {
      "resource_type": "CustomerLocation",
      "resource_id": 7777,
      "name": "Volvo Torslanda",
      "customer_identification_numbers": ["VOL-001"],
      "general_ledger_number": "GL-12345"
    },
    "serving_location": {
      "resource_id": 5050,
      "name": "Torslanda Plant",
      "grouping_type": "customer_location"
    }
  },
  "attributes": {
    "is_loaded": null,
    "train_number": "T-8800"
  },
  "actor": {
    "resource_type": "User",
    "resource_id": 12345,
    "display_name": "ops@customer.com"
  }
}
```

***

## Field Reference

### Top-level Fields

| Field              | Type              | Required | Description                                                                                                                                         |
| ------------------ | ----------------- | -------- | --------------------------------------------------------------------------------------------------------------------------------------------------- |
| `event_type`       | string            | Yes      | Always `"TrainDeparture"` for this event.                                                                                                           |
| `event_timestamp`  | string (ISO 8601) | No       | When the train departed. `null` if unavailable.                                                                                                     |
| `work_order_id`    | string            | No       | ID of the associated work order. `null` if the event has no work order.                                                                             |
| `linked_resources` | object            | Yes      | Equipment, station, and locations involved in the event.                                                                                            |
| `attributes`       | object            | Yes      | Event-specific attributes.                                                                                                                          |
| `actor`            | object or null    | Yes      | Who caused the triggering event. `null` for system-initiated events. See [Shared Payload Fields -> actor](/user-docs/arms/webhooks/overview#actor). |

### linked\_resources.equipment

An array of equipment items on the departing train. Each item includes per-car loaded/empty status. Always an array, even for a single car.

| Field         | Type            | Description                                                         |
| ------------- | --------------- | ------------------------------------------------------------------- |
| `resource_id` | integer         | Internal equipment identifier.                                      |
| `car_number`  | string or null  | Railroad car number (e.g. `"GCGO 995823"`).                         |
| `is_loaded`   | boolean or null | `true` if this car was loaded, `false` if empty. `null` if unknown. |

### linked\_resources.event\_station

The station where the train departed from. `null` if no station could be resolved.

| Field           | Type    | Description                                     |
| --------------- | ------- | ----------------------------------------------- |
| `resource_id`   | integer | Internal station identifier.                    |
| `name`          | string  | Human-readable station name.                    |
| `grouping_type` | string  | Type of location (e.g. `"station"`, `"track"`). |

### linked\_resources.customer\_location

The customer location associated with the departure, if any. The entire object is `null` for departures not associated with a customer location (normal yard departures).

| Field                             | Type             | Description                                                                    |
| --------------------------------- | ---------------- | ------------------------------------------------------------------------------ |
| `resource_type`                   | string           | Always `"CustomerLocation"` when present.                                      |
| `resource_id`                     | integer          | Internal customer location identifier.                                         |
| `name`                            | string           | Human-readable customer location name.                                         |
| `customer_identification_numbers` | array of strings | Carrier-side identifiers for this customer (may be an empty array).            |
| `general_ledger_number`           | string or null   | General ledger number associated with this customer. `null` if not configured. |

### linked\_resources.serving\_location

The serving location associated with the departure, if any. The entire object is `null` when the departure is not tied to a serving location.

| Field           | Type    | Description                                    |
| --------------- | ------- | ---------------------------------------------- |
| `resource_id`   | integer | Internal serving location identifier.          |
| `name`          | string  | Human-readable serving location name.          |
| `grouping_type` | string  | Type of location (e.g. `"customer_location"`). |

### attributes

| Field          | Type            | Description                                                                           |
| -------------- | --------------- | ------------------------------------------------------------------------------------- |
| `is_loaded`    | boolean or null | `true` if cars were loaded, `false` if empty. `null` when status is mixed or unknown. |
| `train_number` | string or null  | Train identifier (e.g. `"T-8800"`). `null` if no train ID is set.                     |

***

## Example HTTP Request

This is the full HTTP request your endpoint receives:

```http theme={null}
POST /your-webhook-endpoint HTTP/1.1
Content-Type: application/json
X-Webhook-Timestamp: 1718614200
X-Webhook-Signature: <base64-encoded-ed25519-signature>
X-Webhook-KeyId: cedar-webhooks-2026
X-Webhook-Id: 550e8400-e29b-41d4-a716-446655440000

{"actor":{"display_name":"ops@customer.com","resource_id":12345,"resource_type":"User"},"attributes":{"is_loaded":null,"train_number":"T-8800"},"event_timestamp":"2026-06-17T09:30:00+00:00","event_type":"TrainDeparture","linked_resources":{"customer_location":{"customer_identification_numbers":["VOL-001"],"general_ledger_number":"GL-12345","name":"Volvo Torslanda","resource_id":7777,"resource_type":"CustomerLocation"},"equipment":[{"car_number":"GCGO 995823","is_loaded":true,"resource_id":100001},{"car_number":"GCGO 726451","is_loaded":false,"resource_id":100002}],"event_station":{"grouping_type":"station","name":"G\u00f6teborg Hamn","resource_id":1001},"serving_location":{"grouping_type":"customer_location","name":"Torslanda Plant","resource_id":5050}},"work_order_id":"a1b2c3d4-e5f6-7890-abcd-ef1234567890"}
```

<Note>
  The JSON body is **canonically serialized** (sorted keys, no extra whitespace) so the signature can be verified
  deterministically. See the [Webhook Overview](/user-docs/arms/webhooks/overview#signature-verification) for verification
  instructions.
</Note>

***

## Differences from Train Arrival

| Aspect                   | Train Arrival                         | Train Departure                                   |
| ------------------------ | ------------------------------------- | ------------------------------------------------- |
| `event_type`             | `"TrainArrival"`                      | `"TrainDeparture"`                                |
| `customer_location`      | Not included in payload               | Included (with `name`, identifiers, GL number)    |
| `serving_location`       | Not included in payload               | Included (with `name`, `grouping_type`)           |
| `linked_resources.track` | Included (arrival track)              | Not included                                      |
| `is_final_location`      | Included in attributes (arrival-only) | Not included                                      |
| Per-car `is_loaded`      | Not included per equipment item       | Included per equipment item                       |
| Trigger                  | Train arrives at a station            | Train departs from a station or customer location |

<Note>
  The Train Arrival webhook does not currently include `customer_location` or `serving_location`, even though the underlying event carries them. This asymmetry is intentional -- if your integration needs location context on both arrival and departure, use the Train Departure webhook for location-aware routing.
</Note>

***

## Setting Up This Webhook

<Steps>
  <Step title="Configure Workflow">In ARMS, create or edit a workflow rule that triggers on train departure events.</Step>

  <Step title="Add Webhook Effect">
    Add the **Train Departure Webhook** effect to the workflow. Provide your endpoint URL.
  </Step>

  <Step title="Implement Your Endpoint">
    Build an HTTPS endpoint that receives the POST, verifies the signature, and processes the event.
  </Step>

  <Step title="Test">Trigger a test event and confirm your endpoint receives and verifies the payload correctly.</Step>
</Steps>

***

## Related

<CardGroup cols={2}>
  <Card title="Webhook Overview" icon="webhook" href="/user-docs/arms/webhooks/overview">
    Signing, verification, public key, and shared HTTP headers.
  </Card>

  <Card title="Train Arrival" icon="train" href="/user-docs/arms/webhooks/train-arrival">
    Webhook for train arrival events at stations.
  </Card>
</CardGroup>