# Authentication started

This event occurs when an [authentication request](https://www.checkout.com/docs/payments/authenticate-payments.md) from a merchant or gateway passes validation.

## Example webhook

```json
{
  "id": "evt_ql5mtq624twrdnpkajbkyeqaai",
  "type": "authentication_started",
  "version": "1.0.1",
  "created_on": "2023-04-26T12:09:41.897Z",
  "data": {
    "session_id": "sid_26tzrqszpi4eppau7ehuyubdxa",
    "amount": "1250",
    "currency": "GBP",
    "type": "regular",
    "response_code": "Y",
    "challenge_indicator": "no_challenge_requested",
    "protocol_version": "2.2.0",
    "scheme": "visa",
	  "payment_id": "pay_w4htz2voa3vujcnuhq263vl7ky",
    "reference": "ORD-5023-4E89"
  },
  "_links": {
    "self": {
      "href": "https://{prefix}.api.checkout.com/workflows/events/evt_ql5mtq624twrdnpkajbkyeqaai"
    }
  }
}
```