x402

An open protocol that uses HTTP 402 so a client can pay a server, usually in USDC, and retry. Named for the reserved HTTP status Payment Required.

Problem: Let a machine pay for an HTTP resource without a human checkout page.
How payment or discovery works: A server that wants to charge responds with HTTP 402 and machine-readable payment requirements. A client that can pay attaches proof and repeats the request. Settlement is typically verified through a facilitator.
Maintainers: x402 Foundation, Coinbase (original public launch)
Networks: Base; Solana; other networks listed in seller documentation
Evidence of adoption: Public launch by Coinbase on 6 May 2025. Linux Foundation announced operational launch of the x402 Foundation on 14 July 2026. Seller documentation lists multiple networks and facilitators.
Last verified by zFinia: 7 September 2026

Membership, listings and facilitator count are not settlement volume. zFinia does not currently publish a verified x402 payment-volume statistic.

Official documentation · Primary source · Explainer

Related: mcp, mpp

Related intelligence

Editorial

TIER_A · standards · Public record

Linux Foundation announces operational launch of the x402 Foundation

On 14 July 2026 the Linux Foundation announced the operational launch of the x402 Foundation and completed contribution of the protocol by Coinbase. Premier members listed include Adyen, AWS, American Express, Circle, Cloudflare, Coinbase, Google, Mastercard, Shopify, Stripe, Visa and others. Membership is not settlement volume.

x402

Event 14 July 2026 · source 14 July 2026 · zFinia published 7 September 2026 · retrospective

Editorial

TIER_A · unmet need · Public record

Paid MCP is still an overlay, not a core MCP feature

MCP specifies how tools are described and invoked. It does not specify settlement. Cloudflare’s gateway, x402 challenge-handoff and MPP all propose to hang payment on the same tool call. Until the MCP spec itself names a payment profile, “paid MCP” remains a market category, not a single standard.

Model Context Protocol (MCP)x402

Event 1 July 2026 · source 1 July 2026 · zFinia published 7 September 2026 · retrospective

Editorial

TIER_A · official announcement · Public record

Cloudflare Monetization Gateway puts x402 on any edge-protected resource

Cloudflare announced a Monetization Gateway waitlist: customers can charge for any Cloudflare-protected asset, with verification at the edge. Launch settlement is described as stablecoins over x402, with work through the x402 Foundation. The post frames per-seat SaaS as a poor fit for one-shot agent requests.

x402

Event 1 July 2026 · source 1 July 2026 · zFinia published 7 September 2026 · retrospective

Editorial

TIER_A · standards · Public record

Linux Foundation announces it is launching the x402 Foundation

On 2 April 2026, at MCP Dev Summit North America, the Linux Foundation announced it is launching the x402 Foundation with contribution of the x402 protocol from Coinbase. Named intending supporters included Cloudflare, Stripe, Visa, Mastercard, Circle, Google and others. This is a governance announcement, not a traffic print.

x402

Event 2 April 2026 · source 2 April 2026 · zFinia published 7 September 2026 · retrospective

Editorial

TIER_B · standards · Public record

x402 Foundation language appears as multi-vendor governance

Cloudflare’s Monetization Gateway announcement describes x402 as an open protocol built with a coalition of industry leaders via the x402 Foundation, with a Linux Foundation launch referenced in contemporaneous reporting. zFinia treats vendor blog claims of foundation status as TIER_B until the foundation’s own charter page is the primary source in-store.

x402

Event 1 April 2026 · source 1 April 2026 · zFinia published 7 September 2026 · retrospective

Editorial

TIER_A · official announcement · Public record

Stripe documents MPP as an internet-native way for agents to pay

Stripe published MPP as an open standard co-authored with Tempo. Agents request an API, MCP server or HTTP resource; the service returns a payment request; the agent authorizes; Stripe businesses see the payment like any other PaymentIntent. Stripe also states payment support for both MPP and x402 inside a broader agentic commerce stack.

Machine Payments Protocol (MPP)x402

Event 18 March 2026 · source 18 March 2026 · zFinia published 7 September 2026 · retrospective