Machine Payments Protocol (MPP)
The Machine Payments Protocol (MPP) is an open specification that finally gives HTTP’s long-reserved 402 Payment Required status code a defined semantics, so a client can pay for a request inside the HTTP exchange instead of provisioning an account first. A server answers with a Challenge in WWW-Authenticate: Payment, the client retries with a Credential in Authorization: Payment, and the server returns the resource with a Payment-Receipt. The core is deliberately payment-method agnostic — cards, stablecoins, Lightning and chain-specific rails are each defined in their own companion draft. It was published on 18 March 2026 by Stripe and Tempo Labs and submitted to the IETF as an individual Internet-Draft.
Also known as MPP, The "Payment" HTTP Authentication Scheme, Payment Auth Scheme, draft-ryan-httpauth-payment.
Providers that carry Machine Payments Protocol (MPP) 4
These providers' own APIs.json profiles carry Machine Payments Protocol (MPP) as a tag — the provider's statement that the standard is part of what it does. APIs.io has not verified the implementation on this page; the de facto profiles on this site are where that measurement exists. Ordered by Kin Score.
Read from the API Evangelist standards directory, facts verified 2026-08-17. Provider links come from the catalog's own identity tags and are rebuilt nightly. If this page is wrong about a standard or a provider, say so.