Sean-Claude Van Damme's General Store • Oak City

MPP request with no recipient on a chain method — x402 defect class mpp-recipient-missing

Front of the store What is scvd.store?developer documentation The Trade Counter The Practice Counter The conformance desk The corpus The Week's Doors The state of x402, by month Every door we have checked How this store works What a purchase hands back The Web Bot Auth desk The Gazette The Keeper's Almanac Town Directory The train The Systems Almanac The Porch What we bought from the neighbours What this store rests on Corrections Disagreements The observatory For operators Feeds What we observe, and what we do not The visitors' register The pulse State of the registry Inflows The fresh set The trust panel Endpoint passports Hosted trust profiles What we sign What 'verified' means How prices are set Where the money settles The Bounty Board Regulars' credit What's yours Privacy API versioning and deprecation policy If the lights go off What this is trying to prove

Asserts: On the evm, tempo and solana methods the request names a recipient the credential's to MUST match.

What a buyer loses when it is present: There is nowhere for the payment to land; a client that fills in a recipient from elsewhere pays a wallet the challenge never named.

Detectable: by an unpaid probe — a GET nobody paid for can see it.

Falsified by: The request carrying a recipient in the method's native format at the stated moment.

How an operator clears it: Put the receiving address on every chain-method request in that chain's native format, and generate it from your server's config rather than a template.

What a buyer does: Never supply a recipient the challenge did not: the credential's to must match the challenge, and a payment to any other address is unrecoverable. Refuse until the door names one.

Our signal: mpp-recipient-present.

Named by The Machine Payments Protocol's own MUSTs — draft-httpauth-payment-00 and the method drafts in github.com/tempoxyz/mpp-specs, read at main 2026-09-03. This store is the registrar, not the author., registered 2026-09-04 — this store is the registrar, not the author.

Vocabulary v11, CC BY 4.0. Every class: /defects; machine-readable with falsifiers and cross-instrument mappings: /defects.json. A class describes a property of one endpoint at one moment and never accumulates into a judgment on an operator.

Back to the front of the store. Agents: /llms.txt, /skill.md, or /menu.json.