Train Departure Webhook - Cedar.AI Documentation

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.

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

Payload Schema

{
  "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.

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:

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"}

The JSON body is canonically serialized (sorted keys, no extra whitespace) so the signature can be verified deterministically. See the Webhook Overview for verification instructions.

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

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.

Setting Up This Webhook

Configure Workflow

In ARMS, create or edit a workflow rule that triggers on train departure events.

Add Webhook Effect

Add the Train Departure Webhook effect to the workflow. Provide your endpoint URL.

Implement Your Endpoint

Build an HTTPS endpoint that receives the POST, verifies the signature, and processes the event.

Test

Trigger a test event and confirm your endpoint receives and verifies the payload correctly.

Webhook Overview

Signing, verification, public key, and shared HTTP headers.

Train Arrival

Webhook for train arrival events at stations.

​Event Overview

​Payload Schema

​Field Reference

​Top-level Fields

​linked_resources.equipment

​linked_resources.event_station

​linked_resources.customer_location

​linked_resources.serving_location

​attributes

​Example HTTP Request

​Differences from Train Arrival

​Setting Up This Webhook

​Related

Webhook Overview

Train Arrival

Event Overview

Payload Schema

Field Reference

Top-level Fields

linked_resources.equipment

linked_resources.event_station

linked_resources.customer_location

linked_resources.serving_location

attributes

Example HTTP Request

Differences from Train Arrival

Setting Up This Webhook

Related