Puedes crear Webhooks para le avisemos a tu servidor cuando pase algo, por ejemplo, un nuevo pedido.

En la pestaña Webhooks de la sección API de tu panel de administración puedes crear un Webhook.

Los datos enviados se enviarán en una llamada POST en un JSON payload con formato:

{
  "data": {
    "order": {
        "_id": "xabAso2p3pKkLMTuz",
        "orderStatus": "pending",
        "isScheduled": false,
        "websiteId": "ErCkmcyCEovseJq5E",
        "code": "15244",
        "fullCode": "#15244-05",
        "userId": "T4wMX9CjX3zpkPxb3",
        "createdAt": "2019-10-11T15:07:50.106Z",
        "address": {
            "placeId": "EihBdmVuaWRhIEhvbGFuZGEgMTYwNSwgUHJvdmlkZW5jaWEsIENoaWxlIjESLwoUChIJCfBr63TPYpYRguPJ8LiSNSgQxQwqFAoSCbELmxJ1z2KWEdvDHqTQ-XrU",
            "address": "Avenida Holanda 1605",
            "addressSecondary": "Providencia, Chile",
            "location": {
            "lat": -33.4334297,
            "lng": -70.59966380000002
            },
            "addressLine2": "1234",
            "comment": "Dejar con el conserje"
        },
        "menuId": "kH2qLySHZ6CdHopNC",
        "deliveryType": "delivery",
        "deliverAt": "2019-10-11T15:24:19.816Z",
        "timeText": "12:34 pm - 12:49 pm",
        "paymentType": "other",
        "otherPaymentType": "Junaeb",
        "tipAmount": 0,
        "amountToPay": 5000,
        "deliveryFee": 2000,
        "itemsPrice": 3000,
        "totalPrice": 5000,
        "baseItemsPrice": 11000,
        "baseTotalPrice": 13000,
        "amountFinancedByJusto": 0,
        "expectedPreparationDuration": 10,
        "deliveryDuration": 10,
        "cashAmount": null,
        "cardId": null,
        "channel": "web-delivery",
        "buyerName": "Nicolás López",
        "phone": "+56979761851",
        "email": "email@example.com",
        "couponName": null,
        "couponDiscount": null,
        "websiteCoinsDiscount": null,
        "itemsPriceBeforeDiscountsAfterProductDiscount": null,
        "store": {
            "_id": "Li4eEa3W2hiuGGCFa",
            "websiteId": "ErCkmcyCEovseJq5E",
            "name": "Colón",
            "acceptDelivery": true,
            "acceptServe": false,
            "acceptGo": true,
            "currentPreparationDuration": 10,
            "currentDeliveryDuration": 10,
            "phone": "+56979761851",
            "address": {
            "placeId": "ChIJjTIDvOLOYpYRX-5Ivi_6UF4",
            "address": "Vasco Núñez de Balboa 1233",
            "addressSecondary": "Las Condes, Chile",
            "location": {
                "lat": -33.42161910000001,
                "lng": -70.5729473
            }
            }
        },
        "items": [
            {
        "product": {
            "_id": "XBHxxGehwFya28dPq",
            "name": "Cebiche de Camarones",
            "externalId": "cebiche-x1"
        },
        "unitPrice": 3000,
        "baseUnitPrice": 11000,
        "amount": 1,
        "comment": "Instrucciones especiales",
        "modifiers": [
            {
            "modifierId": "rkhrzjMYnrR4oJgvK",
            "externalId": "b13",
            "name": "Eleige la bebida",
            "shortName": "Papas fritas",
            "description": "Coca Zero",
            "countById": {
                "ghALK6yqmMYKyBLTr": 1
            },
            "countByExternalId": {
                "zero1": 1
            },
            "options": [
                {
                "_id": "ghALK6yqmMYKyBLTr",
                "name": "Coca Zero",
                "price": 0,
                "externalId": "zero1"
                }
            ]
            }
        ]
        }
        ],
        "transaction": {
            "_id": "AJubbn679CTmgyb6k",
            "totalPrice": 13500,
            "paymentType": "webpayTest",
            "cardType": "credit",
            "cardLast4": "4242",
            "status": "paid",
            "fee": 375,
            "feeWithoutTax": 315
        },
        "deliveries": [
            {
        "_id": "QCevLRgMJfTgSJxhS",
        "price": 1999,
        "status": "done",
        "driverPassword": "5818",
        "activatesAt": "2021-07-20T16:26:00.000Z",
        "createdAt": "2021-07-20T16:12:14.822Z",
        "forDate": "2021-07-20T16:41:43.164Z",
        "fromLocation": {
            "address": "Avenida Vitacura 6345",
            "addressSecondary": "Vitacura, Chile",
            "storeName": "NOMBRE MARCA' Vitacura 6345 (Rotonda Irene Frei)",
            "lat": -33.3902738,
            "lng": -70.5701148
        },
        "toLocation": {
            "address": "Avenida Providencia 1302",
            "addressSecondary": "Providencia, Chile",
            "lat": -33.4286681,
            "lng": -70.6203024
        },
        "nearStoreAt": "2021-07-20T16:16:14.202Z",
        "nearClientAt": "2021-07-20T16:17:32.852Z",
        "completedAt": "2021-07-20T16:18:31.332Z",
        "canceledAt": null,
        "deliveryExpectedAt": "2021-07-20T17:12:00.000Z",
        "driverReceivedAt": "2021-07-20T16:16:32.230Z",
        "deliverProofImage": <URL>,
        "receiveProofImage": <URL>,
        "deliveryInformation": "Maria Soto - Recepción",
        "driverInformation": {
            "type": "moto",
            "phone": "+56999999999",
            "name": "Peter",
            "image": <URL>
        },
        "trackingURL": <URL>,
        "orderId": "wtZnef2Ks7xTfRJ8X",
        "placeName": "Miguel Piedrafitas",
        "instructions": "Dejar el pedido en conserjeria",
        "isCash": true,
        "specialCode": "369",
        "externalId": "ID_EXTERNO",
        "uncompletedReason": "Repartidor sufrió accidente"
        }
        ],
        "devolutions": [
            {
        "_id": "SqmBcwNjv5gqZ2yEm",
        "amount": 7285,
        "category": "Repartidor",
        "reason": "Pedido no entregado por driver",
        "message": "Lo sentimos, no pudimos realizar la entrega de tu producto.",
        "createdAt": "2021-03-02T14:01:51.608Z"
        }
        ],
        "charges": {
            <Resumen de cobros>
        },
        "clonedOrder": null,
        "parentOrder": null,
        "hasManagedDelivery": false,
        "loyaltyTransaction": null,
        "billing:": null,
        "cancellationInfo": {
            "reason": "Sin productos suficientes",
            "reasonMessage": "Lamentamos tener que cancelar tu pedido, pero en estos momentos tenemos problemas para poder ofrecerte el pedido",
            "category": "Productos"
        }
        }
  },
  "date": "2020-01-06T15:36:50.145Z",
  "type": "newOrder"
}

​
Seguridad

Al crear un Webhook debes entrar un clave, que le llamamos secreto. Todas las llamadas que hagamos a tu url van a ser firmadas con esta clave. Así puedes verificar que son datos reales enviados por Justo. La firma es un hash sha-1 del body (en antes de convertir el JSON a objeto) y viene en el header X-Orion-Signature

Para verificar la firma debes hacer lo siguiente:

import JSSHA from 'jssha'

const mySecret = '12345'

// para comprobar que la firma es correcta debemos generarla de nuevo y ver si coincide con la entregada en el request
const checkSignature = (body, passedSignature) => {
  const shaObj = new JSSHA('SHA-1', 'TEXT')
  // usamos la clave que le ingresamos al webhook
  shaObj.setHMACKey(mySecret, 'TEXT')
  // generamos el hash del body
  shaObj.update(body)
  const signature = shaObj.getHMAC('HEX')

  // si son iguales significa que esta verificado
  return passedSignature === signature
}

checkSignature(request.body, headers['x-orion-signature'])