A Shared Payment Token is a single-purpose credential designed for agents. It looks like a card number to a merchant, but it carries built-in restrictions: a maximum amount, a currency, and (often) a single allowed merchant. The agent holds the SPT — never the underlying card or bank account.
SPTs are the abstraction that makes Link CLI, Mastercard Agent Pay, Visa Intelligent Commerce, Affirm, and Klarna all interoperable behind the same agent-facing surface.
Key things to know
Scoped at issue time
The token is minted with the spend boundaries already encoded. There's no separate "now enforce a limit" call — exceeding the cap simply declines on the network.
Backed by anything
Card, bank, BNPL, soon stablecoin. The user picks the funding method when they connect their wallet; the agent never has to know.
Single-use by default
Most flows mint a fresh SPT per task. The agent can't reuse one across purchases unless explicitly granted.
vs. CardForAgent
SPTs are a credential format; CardForAgent issues actual VISA cards with a CVC and expiry. SPTs win for MPP-aware merchants and for crossing payment-method boundaries; cards win for any normal e-commerce checkout that just wants a PAN.