> ## Documentation Index
> Fetch the complete documentation index at: https://docs.monk.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Webhook Events

> Available webhook events and their payload structures

# Webhook Events

Monk sends webhook notifications for customer and invoice changes.

## Available Events

| Event              | Description                                           |
| ------------------ | ----------------------------------------------------- |
| `invoice.created`  | Fired when an invoice is created                      |
| `invoice.updated`  | Fired when an invoice changes status or payment state |
| `customer.created` | Fired when a customer is created                      |
| `customer.updated` | Fired when a customer's data changes                  |

## Payload Shape

Webhook payloads contain the affected resource and its timestamps:

```json theme={null}
{
  "id": "resource-uuid",
  "createdAt": "2026-01-15T10:30:00.000Z",
  "updatedAt": "2026-01-20T14:22:00.000Z"
}
```

The `X-Monk-Event` request header identifies the event type. The `X-Monk-Delivery-Id` header uniquely identifies a delivery for deduplication.

## Invoice Events

Invoice payloads include the invoice number, status, amount, dates, payment link, and customer details.

```json theme={null}
{
  "id": "invoice-uuid",
  "invoiceNum": "INV-001",
  "status": "Paid",
  "totalCents": 150000,
  "invoiceDate": "2026-01-15",
  "dueDate": "2026-02-14",
  "paymentLink": null,
  "customer": {
    "id": "customer-uuid",
    "name": "Acme Corp",
    "legalName": "Acme Corporation Inc.",
    "externalIds": ["salesforce-001"]
  },
  "createdAt": "2026-01-15T10:30:00.000Z",
  "updatedAt": "2026-01-20T14:22:00.000Z"
}
```

## Customer Events

Customer payloads include the customer's public ID, name, legal name, and tags.

```json theme={null}
{
  "id": "customer-uuid",
  "publicId": "cus_Hk7Lm9Np3Qr5Tv8X",
  "name": "Acme Corp",
  "legalName": "Acme Corporation Inc.",
  "tags": ["enterprise", "priority"],
  "createdAt": "2026-01-15T10:30:00.000Z",
  "updatedAt": "2026-02-20T09:15:00.000Z"
}
```

## Invoice Status Values

| Status        | Description                                |
| ------------- | ------------------------------------------ |
| `Drafted`     | Invoice is being prepared                  |
| `In Progress` | Invoice is finalized and ready for payment |
| `In Transit`  | Payment is awaiting reconciliation         |
| `Paid`        | Invoice has been fully paid                |
| `Cancelled`   | Invoice has been cancelled                 |
| `Refunded`    | Invoice has been refunded                  |

See [Webhooks](/concepts/webhooks) for delivery behavior and [Signature Verification](/api-reference/webhooks/verification) before processing a payload.