# Checkout Events

Receive real-time updates when changes occur during order creation and payment processing.

Events allow you to receive real-time updates about order creation and payment processing.

For example, you can receive notifications if an order creation fails, or if a payment authorization succeeds or fails. By subscribing to these events, you can manage your Checkout processes more effectively, ensuring a smoother experience for both you and your customers.

## How to subscribe to Checkout Events

Events use the [Subscriptions API](/api/projects/subscriptions.md), which is separate from the Checkout API. With Subscriptions, you specify a message queue ([destination](/api/projects/subscriptions.md#destination)) which receives the event notifications. This allows you to process events asynchronously, without blocking the Checkout flow.

To subscribe to Checkout Events, create a [SubscriptionDraft](/urn?urn=ctp%3Aapi%3Atype%3ASubscriptionDraft) with the `events` field containing the desired [EventTypes](/api/events.md#eventtype), and post this SubscriptionDraft to the [Create Subscription](/urn?urn=ctp%3Aapi%3Aendpoint%3A%2F%7BprojectKey%7D%2Fsubscriptions%3APOST) endpoint.

The following example SubscriptionDraft subscribes to refund-related events using Google Cloud Pub/Sub as the destination. To subscribe to all Checkout events, do not include any values in the `types` array.

```json
{
  "destination": {
  "type": "GoogleCloudPubSub",
  "topic": "Topic",
  "projectId": "<project-id>"
  },
  "events": [
    {
      "resourceTypeId": "checkout",
      "types": [
                "CheckoutPaymentRefunded",
                "CheckoutPaymentRefundFailed",
            ]
        }
    ]
}
```

## Compare Checkout notification types

Checkout provides multiple notification mechanisms for different layers of your integration. The following table summarizes when to use each type:

| Layer | Type | Delivery | Purpose | Best for |
| --- | --- | --- | --- | --- |
| Frontend | [Checkout Messages](/checkout/messages.md) | Browser SDK callbacks (`onInfo`, `onWarn`, `onError`) | Reflect real-time Session events | UI updates, user feedback, prompting user actions |
| Backend | Checkout Events (this page) | Message queues (such as SQS or Pub/Sub) | Track events related to Checkout Order creation and Payment processing | Checkout process management, backend workflows, logging |
| Backend | [Messages](/api/projects/messages.md) | Message queues (such as SQS or Pub/Sub) | Track resource changes across the platform | Automation, logging, ERP sync |

Use Checkout Messages for immediate, in-browser feedback during a Customer's active session. Use Checkout Events and backend Messages for backend workflows that require reliable, asynchronous processing.

## Representations

### Events

The following Events represent a change or an action related to the Checkout process. Each Event has a `data` field containing [event data](/checkout/checkout-events.md#event-data-payload). This data is specific to a particular change or action.

#### Checkout Order Creation Failed Event

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutOrderCreationFailedEvent).

#### Checkout Payment Authorized Event

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutPaymentAuthorizedEvent).

#### Checkout Payment Authorization Failed Event

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutPaymentAuthorizationFailedEvent).

#### Checkout Payment Charged Event

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutPaymentChargedEvent).

#### Checkout Payment Charge Failed Event

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutPaymentChargeFailedEvent).

#### Checkout Payment Authorization Cancelled Event

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutPaymentAuthorizationCancelledEvent).

#### Checkout Payment Cancel Authorization Failed Event

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutPaymentCancelAuthorizationFailedEvent).

#### Checkout Payment Refunded Event

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutPaymentRefundedEvent).

#### Checkout Payment Refund Failed Event

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutPaymentRefundFailedEvent).

### Event Data Payload

#### Checkout Message Order Payload Base Data

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutMessageOrderPayloadBaseData).

#### Checkout Message Payments Payload Base Data

[type definition](/checkout/checkout-events.md?urn=ctp:api:type:CheckoutMessagePaymentsPayloadBaseData).

## Related pages

- [Area overview page with navigation](/checkout.md)
- [Previous page: Browser SDK](/checkout/browser-sdk.md)
- [Next page: Messages](/checkout/messages.md)