curl -X POST https://api.agentcard.sh/api/v2/webhook_endpoints \
  -H "Authorization: Bearer $ORG_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://your.app/agentcard/webhooks", "enabled_events": ["vault.card_stored", "checkout_authorization.*"], "description": "Production checkout events"}'

{
  "id": "we_7h2k9p4m",
  "object": "webhook_endpoint",
  "url": "https://your.app/agentcard/webhooks",
  "enabled_events": ["vault.card_stored", "checkout_authorization.*"],
  "status": "active",
  "description": "Production checkout events",
  "secret": "whsec_…"
}