curl --request PUT \
  --url https://api.onkernel.com/vaults/{id_or_name}/items/{key} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "spec": {
    "amount": 2599,
    "card_id": "vc_example",
    "currency": "usd",
    "merchant": "Example Store",
    "provider": "agentcard",
    "wallet": "agentcard-wallet"
  },
  "type": "card"
}
'

{
  "available_expansions": [],
  "available_operations": [],
  "created_at": "2026-01-01T12:00:00Z",
  "id": "card_agentcard_example",
  "key": "agentcard-card",
  "spec": {
    "amount": 2599,
    "card_id": "vc_example",
    "currency": "usd",
    "merchant": "Example Store",
    "provider": "agentcard",
    "wallet": "agentcard-wallet"
  },
  "state": {
    "aliases": {
      "cvc": "123",
      "exp_month": "12",
      "exp_year": "2030",
      "number": "4242424242424242"
    },
    "provider": "agentcard",
    "status": "ready"
  },
  "type": "card",
  "updated_at": "2026-01-01T12:00:00Z"
}