subscriptions, travel, one-off) and the agent picks which one to charge for each transaction.
The card model
Lifecycle
Operations
Issue a card
Card selection at transaction time
Reference a card on every intent. Pass eithercardId or cardName (within the agent). Omitting both returns E_CARD_REQUIRED — there is no implicit default card by design.
DPAN — the only card identifier the merchant sees
The DPAN (Device Primary Account Number) is a network token issued by Visa’s tokenization service through the banking partner. It’s:- Deterministically derived from the FPAN
- Non-reversible — useless if leaked
- Auto-updates across merchants when the underlying card is rotated
Fill tokens (ftok_*)
Internal-only encrypted wrappers for PAN/CVV/expiry. Used inside the credential flow, never returned to agents. If you see ftok_ in your logs, our sanitizer missed something — file a bug.
Card-controls sync
Spend caps, MCC allow/block, country allow/block on the policy attached to the card’s agent are pushed to the card-issuer-native control surface. Policy is the source of truth; the card mirror is a best-effort projection.Webhooks
Plan-tier limits
Next
Agents
The owner of every card.
Policies
What governs each card’s spending.
Pay
How a card actually charges.
Transactions
The record every successful charge writes.
