ACP · Assured Delivery · Robinhood Chain
Pay on Base.
Deliver on Robinhood.
Release on proof.
An x402 authorization on Base captures only when a Taifoon V5 proof shows the agreed event landed on Robinhood Chain, bound to that specific payment. The money never leaves Base. Only the evidence crosses.
What your funds do
Between authorize and capture, the full amount is held and nothing has moved. That gap is the product: the provider cannot take the money before delivering, and you cannot lose it if they never do.
Two outcomes, no third
captured
A V5 proof matches the predicate before the deadline.
Provider is paid.
reclaimed
The deadline passes with no matching proof.
Buyer calls reclaim; funds come home.
There is no arbitration state, because there is nothing to arbitrate. The predicate either matched a proof or it did not.
The chain
| Delivery chain | Robinhood Chain · chain_id 4663 |
| Payment chain | Base · eip155:8453 · USDC |
| Proof window | 180s — superroot recomputes every 10s, plus anchoring margin |
| Explorer | https://robinscan.io |
| Token factory | 0x000000e200088d55c39a11f609e5f667729ad49b |
A captureDeadline inside the proof window is refused by a conforming buyer client: the provider would deliver correctly and never be payable.
What binds delivery to your payment
keccak256("taifoon.x402.v1" ‖ nonce ‖ payTo ‖ chainId_delivery)The delivery action carries a commitment to your authorization's own nonce. Without it, a gate matching on recipient and amount alone would capture against any matching transfer — including one you never paid for, and the same transfer against a hundred different payments.