Train Set Webhook - Cedar.AI Documentation

Event Overview

The Train Set webhook fires when a train consist is defined in ARMS — typically when wagons are assigned to a train with departure and arrival stations. It delivers the wagon list, station details (including names), train identifier, and the associated work order (if any).

This webhook is triggered through ARMS workflow automation. Configure it in your workflow rules to notify external systems when a train consist is set up.

Payload Schema

{
  "event_type": "train_set",
  "event_timestamp": "2026-03-09T14:30:00+00:00",
  "work_order_id": "12345",
  "linked_resources": {
    "equipment": [
      {
        "resource_id": 2001,
        "car_number": "GCGO 11111"
      },
      {
        "resource_id": 2002,
        "car_number": "GCGO 22222"
      },
      {
        "resource_id": 2003,
        "car_number": "GCGO 33333"
      }
    ],
    "departure_station": {
      "resource_id": 6001,
      "name": "Hallsberg",
      "grouping_type": "station"
    },
    "arrival_station": {
      "resource_id": 6002,
      "name": "Gothenburg",
      "grouping_type": "station"
    }
  },
  "attributes": {
    "train_id": "T-9876"
  },
  "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 `"train_set"` for this event.
`event_timestamp`	string (ISO 8601)	No	When the event occurred. `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, departure station, and arrival station for the train.
`attributes`	object	Yes	Event-specific attributes (train identifier).
`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 wagons assigned to the train. Always an array, even for a single wagon.

Field	Type	Description
`resource_id`	integer	Internal equipment identifier.
`car_number`	string or null	Railroad car/wagon number (e.g. `"GCGO 11111"`).

linked_resources.departure_station

The station where the train departs from. null if no departure station is associated.

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.arrival_station

The station where the train arrives. null if no arrival station is associated.

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"`).

attributes

Field	Type	Description
`train_id`	string	Train identifier (e.g. train number or code).

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: 1709651400
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":{"train_id":"T-9876"},"event_timestamp":"2026-03-09T14:30:00+00:00","event_type":"train_set","linked_resources":{"arrival_station":{"grouping_type":"station","name":"Gothenburg","resource_id":6002},"departure_station":{"grouping_type":"station","name":"Hallsberg","resource_id":6001},"equipment":[{"car_number":"GCGO 11111","resource_id":2001},{"car_number":"GCGO 22222","resource_id":2002},{"car_number":"GCGO 33333","resource_id":2003}]},"work_order_id":"12345"}

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.

Setting Up This Webhook

Configure Workflow

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

Add Webhook Effect

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

Map Inputs

Wire the departure station, arrival station, equipment (wagons), and train ID from the trigger event to the effect inputs.

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.

Car Actually Placed

Fires when a car is placed at a station or track.

Train Departure

Fires when a train departs from a station or customer location.

​Event Overview

​Payload Schema

​Field Reference

​Top-level Fields

​linked_resources.equipment

​linked_resources.departure_station

​linked_resources.arrival_station

​attributes

​Example HTTP Request

​Setting Up This Webhook

​Related

Webhook Overview

Car Actually Placed

Train Departure

Event Overview

Payload Schema

Field Reference

Top-level Fields

linked_resources.equipment

linked_resources.departure_station

linked_resources.arrival_station

attributes

Example HTTP Request

Setting Up This Webhook

Related