Protocol intelligence / Payments

Machine Payments Protocol

A payment protocol for machine consumption of web services.

Specification state: draftPrimary evidence available

StewardMPP / Tempo and Stripe contributors

Stack layerPayments

Versiondraft-httpauth-payment-01 · normative core; broader SDK/method versions separate

Last evidence check28 September 2026

Merchant answer / Source-backed reference

A payment protocol for machine consumption of web services. Lets agents negotiate and pay for service access across supported payment methods. Does not supply retail catalogs, fulfillment or a complete store checkout. Individual merchant eligibility and deployed configuration require confirmation.

What this establishes
The documented role and version scope in the source ledger.

What it cannot establish
Live merchant deployment, private account eligibility, purchase completion or guaranteed AI selection.

Claim-to-source mapping

description: A payment protocol for machine consumption of web services. · verified · Checked 2026-09-28 · Sources: mpp-home, mpp-x402
Scope: Public documentation; not an authenticated merchant test
role: Lets agents negotiate and pay for service access across supported payment methods. · verified · Checked 2026-09-28 · Sources: mpp-home, mpp-x402
Scope: Public documentation; not an authenticated merchant test
version: Unknown · unknown-after-research · Checked 2026-09-28 · Sources: mpp-home, mpp-x402
Scope: Public documentation; not an authenticated merchant test
version: draft-httpauth-payment-01 · normative core; broader SDK/method versions separate · verified · Checked 2026-09-28 · Sources: v11-mpp-ietf
Scope: Normative core draft linked by MPP; not a single version for every MPP payment method/SDK

Evidence dates and document versions remain attached to the ledger below. Editorial presentation reviewed 30 September 2026; this is not a new source verification.

Version-aware protocol intelligence

Current version. Clear scope.

Current versiondraft-httpauth-payment-01

Current statusactive individual Internet-Draft

Published date2026-09-09

First observed / last verified2026-09-28 / 2026-09-28

Date printed in the IETF draft.

Scope: Normative core draft linked by MPP; not a single version for every MPP payment method/SDK · Layer: Payments · Steward: MPP / Tempo and Stripe contributors

Merchant impact

MPP docs point to the Payment HTTP Authentication Scheme core draft, revision 01. It is not an IETF-endorsed standard.

Pin the core draft and payment-method documents separately. Do not substitute an SDK version for a protocol release.

Public implementation evidence: Team documents service integrations; not independently transacted

Merchant action today: Identify a paid API/resource use case.

Unknowns: Your enabled version, provider rollout, plan and region require merchant-side confirmation.

MPP authors / IETF Datatracker version source ↗

Source capture hashes

v11-mpp-ietf: SHA-256 fcb287fd83f5a74d9ebf5b06ade3849cbad9ca4581a88fc075554afc28956b69

Previous versions

Retrospective source research, first observed by us in September 2026. This is a reviewed subset, not a claim of complete upstream release history.

No earlier version is verified in this record. Unknown is not proof that none exists.

Documented role

What it helps with

Lets agents negotiate and pay for service access across supported payment methods.

Keep the scope clear

What it does not solve

Does not supply retail catalogs, fulfillment or a complete store checkout.

The merchant work

Identify a paid API/resource use case.
Confirm accepted methods and spending limits.
Keep credentials outside any public scanner.

Individual merchant eligibility and deployed configuration require confirmation.

Version	draft-httpauth-payment-01 · normative core; broader SDK/method versions separate verified · 2026-09-28
Discovery	Payment offers for services verified · 2026-09-28
Checkout	Not a retail checkout model verified · 2026-09-28
Payment	Core role: service access verified · 2026-09-28
Authorization	Payment method and intent dependent verified · 2026-09-28
Transport	HTTP-oriented; SDK integration verified · 2026-09-28
Adoption	Team documents service integrations; not independently transacted verified · 2026-09-28

Compare protocols ↗

Append-only history

What we observed, and when.

First house observation: 28 September 2026. Earlier dates, where known, are effective dates researched retrospectively.

2026-09-09

Effective date

Scope clarified

draft-httpauth-payment-01 · normative core; broader SDK/method versions separate; 1 scoped version record(s) now linked.

Before / previous scope

V1 record: Unknown; no structured prior-version timeline.

Observed evidence

draft-httpauth-payment-01 · normative core; broader SDK/method versions separate; 1 scoped version record(s) now linked.

Merchant impact: Pin the core draft and payment-method documents separately. Do not substitute an SDK version for a protocol release.

First captured by us: 2026-09-28. Earlier effective dates are researched retrospectively.

MPP authors / IETF Datatracker source ↗View entity →

Open the September baseline →

Evidence ledger

Go to the source.

Primary documentation records what is publicly stated. It does not independently prove outcomes or your account’s eligibility.

Machine Payments Protocol
MPP · official primary · Checked 2026-09-28
Claim scope: Agent payments for web services
Open payment-method-extensible protocol; no retail-wide adoption inferred.
Source ID: mpp-home · Published: Not stated
EVM and x402 support
MPP · official primary · Checked 2026-09-28
Claim scope: SDK interoperability
MPP team documents x402 exact flows in mppx.
Source ID: mpp-x402 · Published: 2026-06-08
Mpp Ietf — V1.1 source capture
MPP authors / IETF Datatracker · official primary · Checked 2026-09-28
Claim scope: Version metadata and documented changes only; not merchant adoption.
SHA-256 of retrieved source response: fcb287fd83f5a74d9ebf5b06ade3849cbad9ca4581a88fc075554afc28956b69
Source ID: v11-mpp-ietf · Published: Not stated

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