generated: '2026-07-18'
method: searched
source: https://docs.cedarai.com/user-docs/arms/webhooks/overview
spec_type: Webhooks
summary: >-
  Cedar ARMS "Workflow Effect" webhooks deliver real-time operational events as
  signed HTTP POST requests. A configured workflow event fires in ARMS, Cedar
  builds a JSON payload, signs it with Ed25519, and POSTs it to the customer's
  HTTPS endpoint over HTTP/2 (HTTP/1.1 fallback).
delivery:
  transport: https-post
  content_type: application/json
  signing: Ed25519 (verify with Cedar public key)
  headers:
    - name: X-Webhook-Timestamp
      description: Unix epoch seconds when the request was sent.
    - name: X-Webhook-Signature
      description: Base64-encoded Ed25519 signature of the payload.
    - name: X-Webhook-KeyId
      description: Identifier of the signing key used (e.g. cedar-webhooks-2026).
    - name: X-Webhook-Id
      description: UUID v4 for deduplication.
events:
  - event_type: car_actually_placed
    name: Car Actually Placed
    description: Sent when a car is placed at a station or track.
    docs: https://docs.cedarai.com/user-docs/arms/webhooks/car-actually-placed
  - event_type: TrainArrival
    name: Train Arrival
    description: Sent when a train arrives at a station.
    docs: https://docs.cedarai.com/user-docs/arms/webhooks/train-arrival
  - event_type: TrainDeparture
    name: Train Departure
    description: Sent when a train departs from a station.
    docs: https://docs.cedarai.com/user-docs/arms/webhooks/train-departure
  - event_type: train_set
    name: Train Set
    description: Sent when a train consist is defined with wagons and route stations.
    docs: https://docs.cedarai.com/user-docs/arms/webhooks/train-set