> ## Documentation Index
> Fetch the complete documentation index at: https://circle-devdocs-test-ai-codegen-component.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# How-to: Set up Webhook Notifications

During the payment process, CPN sends notifications using webhooks. These
asynchronous notifications inform the entities on the progress of the payment
and any required actions they must take.

This guide demonstrates how to subscribe to CPN notifications as an OFI
integrator. See [Webhook Events](/cpn/references/webhook-events) for a complete
list of the notifications that are sent over webhooks.

## Steps

Use the following steps to set up a webhook endpoint and subscribe to
notifications using the CPN API.

### Step 1: Set up a subscriber endpoint

To receive webhook notifications, you must expose a publicly accessible
subscriber endpoint. The endpoint must be able to handle both `HEAD` and `POST`
requests over HTTPS.

<Note>
  **Note:** During OFI integration, Circle works directly with you to configure
  this endpoint.
</Note>

For testing purposes, you can create an endpoint using
[webhook.site](https://webhook.site).

### Step 2: Subscribe to notifications

Set up an endpoint to receive notifications instead of polling for event updates
using the `/v2/subscriptions` endpoint.

```shell Shell theme={null}
curl --request POST \
  --url https://api.circle.com/v2/cpn/notifications/subscriptions \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer ${YOUR_API_KEY}:' \
  --header 'Content-type: application/json' \
  --data '
{
    "endpoint": "${YOUR_WEBHOOK_ENDPOINT}",
    "name": "Test OFI",
    "enabled": true,
    "notificationTypes": ["*"]
}
'
```

**Response**

```json JSON theme={null}
{
  "data": {
    "id": "1609aa1c-510a-448d-b9b9-3a13566ff922",
    "name": "Test OFI",
    "endpoint": "https://webhook.site/1fde07a9-8974-42bd-a273-943ffdf0e7d6",
    "enabled": true,
    "createDate": "2025-05-08T16:20:02.825689Z",
    "updateDate": "2025-05-08T16:20:02.825689Z",
    "notificationTypes": ["*"],
    "restricted": false
  }
}
```

Webhook notifications are digitally signed with an asymmetric key. You can use
information in the webhook header to verify that the content of the webhook is
legitimate. For more information, see
[How-to: Verify Webhook Signatures](/cpn/howtos/verify-webhook-signatures).