Pay an order that waits for payment, as an agent, without a person: HTTP 402. An Audit Drive (audit, $499, plus its paid plan and its payment test at cost when it has them), and its renewal (renewal, $199), for a domain you verified (else 403 claim_not_verified). A Stack check (stack3, $490; stack, $1,490 for 5 tools and $250 for each extra tool) and a data plan (builder, $49 a month; team, $290 a month), with no domain to verify. The same prices as the card checkout. Paid over HTTP 402, a data plan runs one month and doesn't renew by itself: pay again before it ends and the next month follows on. We email you 3 days before it ends. A data plan's month is on your API key as soon as it's paid. Without a credential: 402 with the challenges. Pay one and send the same request again with the credential (Authorization: Payment for MPP, PAYMENT-SIGNATURE for x402): the paid order, its drive queued, and the receipt (Payment-Receipt or PAYMENT-RESPONSE). No key needed: the order's id is enough. An order waits 24 hours for its payment (409 expired); paid already: 409 already_paid; one payment at a time (409 payment_in_progress). On a person's account the card checkout works too (payment.url in the answer to POST /api/orders); an agent's own account has none until a person claims it. The 402's fix and payment.agent.how name only the rails that are on now.