Who built x402 and who governs it? From Coinbase to the Linux Foundation

Who built x402 and who governs it? From Coinbase to the Linux Foundation

Coinbase built x402 and released it in May 2025; since 14 July 2026 its specification has been governed by the x402 Foundation, which operates under the Linux Foundation and has 40 members, including Visa, Mastercard, American Express, Stripe, Google, Amazon Web Services, Cloudflare, Shopify, Circle and Coinbase itself. The story of x402's first sixteen months is mostly a story of one company building a protocol and then working to make it not its own. A neutral foundation governs the specification, though not the infrastructure that most payments pass through.

This is the fourth chapter of the Group's book *The x402 Economy*, rewritten as a standalone article, current to 27 September 2026.

What is the timeline of x402?

Sources: CoinDesk (11 December 2025 and 2 April 2026), the Linux Foundation's 14 July 2026 announcement, Cloudflare's Monetization Gateway post, Chainalysis and Stripe's MPP announcement. The specification itself is public on GitHub: x402 version 2, and the project site is x402.org.

Why did Coinbase build x402?

Coinbase runs a cryptocurrency exchange, a set of developer products and the Base network. It also helped create USDC and shares in its economics. A protocol that makes USDC the ordinary way for software to pay for things on the web serves every part of that business: more USDC in use, more transactions on Base, more developers using Coinbase's tools, and more settlements through Coinbase's facilitator.

Coinbase has been open about the problem it set out to solve. At the Foundation's launch, Lincoln Murr of Coinbase said: "x402 was started at Coinbase to solve a real problem – AI agents had no native, interoperable way to pay for the things they needed to do."

A protocol that serves one company's interests is hard for that company's competitors to adopt. Stripe, Google, Visa and Mastercard have little reason to build their agent payment plans on a standard Coinbase controls. The second half of the timeline is Coinbase addressing that.

Who is in the x402 Foundation?

The Linux Foundation is a nonprofit that hosts widely shared software such as the Linux kernel and Kubernetes. The x402 Foundation launched operationally on 14 July 2026 with 17 premier members:

• Card networks and processors: Adyen, American Express, Fiserv, Mastercard, Stripe and Visa.
• Cloud and web companies: Amazon Web Services, Cloudflare, Google and Shopify.
• Crypto companies and foundations: Circle, Coinbase, the Monad Foundation, MoonPay, Ripple, the Solana Foundation and the Stellar Development Foundation.

Eighteen general members joined as well, from crypto infrastructure firms and blockchain foundations to KakaoPay and World Liberty Financial, and five associate members: forty in all. Jim Zemlin, the Linux Foundation's chief executive, framed the purpose this way: "AI agents and automated systems are becoming active participants in the global economy, yet they have lacked a native, secure way to transact."

The membership list shows how the protocol changed status in a year. Visa, Mastercard and American Express run the card networks that stablecoin payments might someday compete with. Stripe publishes a rival protocol. Google publishes a protocol for authorizing agent purchases. All of them joined.

Why do rivals join a standard started by a competitor?

Three ordinary reasons.

Standards are cheaper shared. If every payment company defined its own 402 format, every seller would have to support all of them and every agent would have to speak all of them. A shared format grows the whole market, including each member's part of it.

Membership buys a voice. A premier member of a foundation helps decide what the next version says. A company outside the foundation must adapt to whatever the members decide.

Joining costs little and hedges much. Nobody knows yet which agent payment protocols will carry real volume. Joining x402's foundation while building or backing another protocol lets a company be present wherever the volume goes. Stripe accepts x402 and publishes its own protocol. Google backs x402 and publishes AP2. These protocols mostly solve different parts of the problem, which makes hedging easier.

What does the x402 Foundation not govern?

A neutral foundation governs the specification. It does not govern the infrastructure that most x402 payments pass through.

• Coinbase runs the dominant facilitator, and settlement through it depends on its screening policies and pricing.
• Base, Coinbase's network, is one of the two main blockchains for x402 traffic. In mid-2026 reports put Solana ahead by count of transactions.
• Circle issues USDC and can freeze tokens at an address.
• Discovery depends partly on catalogs run by interested parties. One widely used x402 explorer is operated by a foundation member and charges for its own data through x402, as the writer Daniel McGlynn noted.

None of this is unusual. Card payments follow open standards and still flow through a few large processors and networks. It does mean that "open protocol" describes the rules, not who carries the traffic. A seller depends on companies other than its customers: a facilitator can stop serving a category of business, an issuer can freeze an address, a network can change its fees. Sellers who care can use more than one facilitator, which version 2 supports, and accept payment on more than one network. The Group's own market uses Coinbase's developer-platform facilitator, with USDC on Base.

What did the Foundation's formation change?

• For protocol stability: the specification has a neutral home, public versioning (version 2 introduced standard headers, CAIP-2 network names, extensions and sessions) and a body in which payments companies can propose changes.
• For sellers: the tooling is broader. Cloudflare's Monetization Gateway lets a publisher behind Cloudflare put a price on pages, datasets, APIs or AI tool calls with payment checked at the edge and settled through x402. Market analysts in August 2026 pointed to the gateway as the most likely source of new x402 demand in late 2026; whether crawler operators will pay rather than go elsewhere is not yet known.
• Not for volume: foundation membership is not demand. As the market-size numbers show, genuine commerce on x402 is in the tens of millions of dollars, and daily volume fell about 93% in the first half of 2026 from a speculative peak.

What should I take from this?

• Coinbase released x402 in May 2025, released version 2 in December 2025, and moved the protocol into a Linux Foundation body that launched in July 2026.
• The foundation's members include the card networks, the largest cloud providers, Stripe, Google and major crypto companies, several of which back other agent payment protocols too.
• Rivals join because shared standards grow the market, membership buys a voice, and joining hedges an uncertain outcome.
• The foundation governs the specification. The facilitators, networks and stablecoin issuers that carry most payments remain a small set of companies.

Continue with What is x402?, the step-by-step payment walkthrough or the legal picture around the stablecoin x402 settles in.