Webhook events

assistant_message.cancelled

Delivered when an assistant message is cancelled.

postWebhookassistant_message.cancelled

Payload

event'assistant_message.succeeded' | 'assistant_message.failed' | 'assistant_message.cancelled' required

Lifecycle events for assistant messages started via the developer API.

messageIdstring required

Opaque assistant message id (e.g. vg_mesg_...).

occurredAtinteger required

Seconds since epoch (Unix timestamp) when the message reached a terminal state.

Acknowledge receipt

Webhooks have no change history: a webhook is keyed by its event name rather than a path and method, so no recorded change can name it.