# Send call events
<a name="whatsapp-calling-events"></a>

You send WhatsApp call events, such as connecting or ending a call, using the `SendWhatsAppCallEvent` operation. AWS End User Messaging Social passes the call event through to Meta's calling API. The operation returns the call identifier that Meta assigns to the call.

The request includes the origination phone number, the version of the Meta Graph API to use, and the call event. The call event is a JSON payload in the format defined by Meta's calling API, and AWS End User Messaging Social passes it through without modification. The Meta Graph API version and the call event format are defined by Meta. For the call event schema and supported API versions, see the [WhatsApp calling documentation](https://developers.facebook.com/docs/whatsapp/cloud-api/calling) from Meta.

Because `SendWhatsAppCallEvent` is asynchronous, you receive a handover event that reports the outcome after your call event is handed off to WhatsApp. The outcome is either WhatsApp Call Handover Succeeded or WhatsApp Call Handover Failed. The failure event includes the error that explains why the hand-off failed. To receive these events, turn on event publishing for the WABA. To correlate a handover event with the call event that produced it, include a `biz_opaque_callback_data` value in the call event; you receive the same value back on the handover event. For more information, see [Events generated by AWS End User Messaging Social](managing-event-destinations-generated.md).