Business
├── Programs  (contractual envelope — one per agreement with FYATU)
│   └── Products  (card templates — up to 5 per program)
│       └── Cards  (inherit all settings from the product)
│
├── Cardholders  (business-level — not linked to any program)
└── Transactions  (business-level — spans all programs)

You top up the ledger via the portal
              │
              ▼
        Program ledger
              │
    ┌─────────┴──────────┐
    │                    │
POST /cards/{id}/fund   POST /cards/{id}/unload
POST /cards/{id}/terminate (refund)
    │                    │
    ▼                    ▼
  Card balance     Card balance

Program: Visa USD Agreement
└── Products:
    ├── "Visa USD Standard"   — $5,000 limit, 3DS on, tokenization off
    ├── "Visa USD Premium"    — $20,000 limit, 3DS on, tokenization on (Apple/Google Pay)
    └── "Visa USD Restricted" — $500 limit, no 3DS, JIT funding enabled

curl https://api.fyatu.com/api/v3.20/programs/prg_01HXYZ.../products \
  -H "Authorization: Bearer $FYATU_API_KEY"

POST /cards
{
  "cardholderId": "chl_01HXYZ1234ABCDEF5678",
  "productId":    "prd_01HXYZABC123"
}

"spendingLimitPerCard": {
  "cents":        500000,
  "displayValue": "5000.00"
}