{ "$schema": "https://json-schema.org/draft/2020-12/schema", "$id": "https://developer.grubhub.com/schemas/grubhub/ordercancellationpayload.json", "title": "Grubhub Order Cancellation Payload", "description": "Webhook payload for an order cancellation event.", "type": "object", "properties": { "event_type": { "type": "string", "description": "The type of event that triggered this webhook.", "const": "ORDER_CANCELLED", "example": "STANDARD" }, "order_uuid": { "type": "string", "format": "uuid", "description": "The unique identifier for the cancelled order.", "example": "3fa85f64-5717-4562-b3fc-2c963f66afa6" }, "merchant_id": { "type": "string", "description": "The Grubhub merchant identifier.", "example": "ghm-1234567890" }, "cancelled_by": { "type": "string", "description": "Who initiated the cancellation.", "enum": [ "DINER", "MERCHANT", "SYSTEM" ], "example": "DINER" }, "reason": { "type": "string", "description": "The reason for cancellation.", "example": "Out of an item." }, "cancelled_at": { "type": "string", "format": "date-time", "description": "When the order was cancelled.", "example": "2026-06-02T18:30:00Z" } } }