Protocol intelligence / Payments

x402

An internet payment standard built around HTTP payment negotiation.

Specification state: livePrimary evidence available

Stewardx402 Foundation / contributors

Stack layerPayments

Version2

Last evidence check28 September 2026

Merchant answer / Source-backed reference

An internet payment standard built around HTTP payment negotiation. Connects a resource request to payment requirements and a paid retry. Does not describe a retail order, shipping policy or return workflow. Individual merchant eligibility and deployed configuration require confirmation. Map this role to your existing stack and confirm the exact version, access conditions and implementation scope before making a merchant decision.

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: An internet payment standard built around HTTP payment negotiation. · verified · Checked 2026-09-28 · Sources: x402-spec, x402-site
Scope: Public documentation; not an authenticated merchant test
role: Connects a resource request to payment requirements and a paid retry. · verified · Checked 2026-09-28 · Sources: x402-spec, x402-site
Scope: Public documentation; not an authenticated merchant test
version: Unknown · unknown-after-research · Checked 2026-09-28 · Sources: x402-spec, x402-site
Scope: Public documentation; not an authenticated merchant test
version: 2 · verified · Checked 2026-09-28 · Sources: v11-x402-v2
Scope: Protocol specification

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 version2

Current statuspublished specification

Published dateUnknown

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

Publication timestamp not established; date-like version labels are not assumed to be publication timestamps.

Scope: Protocol specification · Layer: Payments · Steward: x402 Foundation / contributors

Merchant impact

Version 2 separates the core payment model from transport and scheme specifications.

Select a compatible transport, scheme and facilitator; do not treat payment-resource access as full retail checkout.

Public implementation evidence: Public implementations; merchant deployment Unknown

Merchant action today: Choose supported network and payment scheme.

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

x402 maintainers version source ↗

Source capture hashes

v11-x402-v2: SHA-256 aa6dc5e8ccc7758689945fc7502674f51cd0f21f09ec886aa1dbc4cd86bc81b6

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.

1 historical specification

Published Unknown · First observed 2026-09-28

The repository retains Protocol Version 1.

Merchant impact: Check the message version of an existing integration before adopting Version 2.

Publication timestamp not established; date-like version labels are not assumed to be publication timestamps.

Version source ↗

Documented role

What it helps with

Connects a resource request to payment requirements and a paid retry.

Keep the scope clear

What it does not solve

Does not describe a retail order, shipping policy or return workflow.

The merchant work

Choose supported network and payment scheme.
Define resource pricing and settlement verification.
Treat published network support as configuration-specific.

Individual merchant eligibility and deployed configuration require confirmation.

Version	2 verified · 2026-09-28
Discovery	Resource-specific payment requirements verified · 2026-09-28
Checkout	Outside retail checkout scope verified · 2026-09-28
Payment	HTTP 402 payment flow verified · 2026-09-28
Authorization	Scheme-dependent verified · 2026-09-28
Transport	HTTP-native verified · 2026-09-28
Adoption	Public implementations; merchant deployment Unknown 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.

2026-09-28

Capture date

Evidence improved

2; 2 scoped version record(s) now linked.

Before / previous scope

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

Observed evidence

2; 2 scoped version record(s) now linked.

Merchant impact: Select a compatible transport, scheme and facilitator; do not treat payment-resource access as full retail checkout.

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

x402 maintainers 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.

x402 repository
x402 project · official primary · Checked 2026-09-28
Claim scope: HTTP payment flow
Repository says canonical development moved to x402 Foundation; Coinbase repo is a development fork.
Source ID: x402-spec · Published: Not stated
x402 official site
x402 · official primary · Checked 2026-09-28
Claim scope: Internet-native payments
Source ID: x402-site · Published: Not stated
X402 V2 — V1.1 source capture
x402 maintainers · official primary · Checked 2026-09-28
Claim scope: Version metadata and documented changes only; not merchant adoption.
SHA-256 of retrieved source response: aa6dc5e8ccc7758689945fc7502674f51cd0f21f09ec886aa1dbc4cd86bc81b6
Source ID: v11-x402-v2 · Published: Not stated

Dispute a fact or suggest a source