Do x402 and MPP compete?

They are parallel options at the same settlement layer rather than a commerce-versus-payment split, and they target the same use cases: agent-to-agent payments, microtransactions, and paying per API call. But they are not mutually exclusive. Stripe explicitly supports both, so a service could accept either.

Which should I use, x402 or MPP?

If you want pure on-chain stablecoin settlement and a crypto-native facilitator model, x402 fits. If you want to accept machine payments alongside your existing card and wallet flows through one provider, MPP through Stripe is the easier lift. Because Stripe supports both, the decision often comes down to whether you want stablecoin-only or mixed settlement.

x402 vs MPP: Comparing the Machine-Native Payment Protocols

Q: What is the difference between x402 and MPP?

Both are machine-native settlement standards built on the HTTP 402 'Payment Required' status, for software paying software rather than consumer checkout. x402 is Coinbase's stablecoin-focused protocol, settling on-chain through a facilitator. MPP is Stripe and Tempo's, settling in stablecoins as well as the cards, wallets, and other methods Shared Payment Tokens carry. The shared mechanism is the same; the difference is sponsorship, settlement breadth, and rails.

x402 and MPP are the two machine-native settlement standards: both are built on the HTTP 402 “Payment Required” status, and both exist for software paying software, an agent paying for an API call, compute, data, or a digital service, rather than a person checking out. x402 is Coinbase’s stablecoin-focused protocol. MPP, the Machine Payments Protocol, is Stripe and Tempo’s, and settles in stablecoins as well as the cards, wallets, and other methods Shared Payment Tokens carry. They sit at the same layer of the stack, and Stripe supports both, so they are best understood as parallel options rather than a winner-take-all rivalry.

At a glance

	x402	MPP
Full name	x402	Machine Payments Protocol
Led by	Contributed by Coinbase, now the x402 Foundation	Stripe and Tempo
Launched	2025	March 2026
Built on	HTTP 402 “Payment Required”	HTTP 402 “Payment Required”
Settles in	Stablecoins in practice (for example USDC); the spec is network, token, and currency agnostic	Stablecoins, plus the cards, wallets, and other methods carried by Shared Payment Tokens
Rails	On-chain, via a facilitator	Tempo and Solana for crypto, Stripe’s card rails via Shared Payment Tokens
Governance	x402 Foundation, operational under the Linux Foundation since 14 July 2026 with 40 members	Tempo Labs and Stripe; core submitted to the IETF as an individual Internet-Draft, no working group yet
Best for	Crypto-native, on-chain settlement	Mixed settlement through one provider

What each one is

x402 revives the long-dormant HTTP 402 status so a service can demand payment inline: a client requests a resource, the server responds with a payment requirement, the client pays, and a facilitator verifies and settles the payment on-chain before the resource is delivered. It is stablecoin-native and aimed at a decentralized agent ecosystem. For the basics, see the glossary entry.

MPP standardizes the same kind of inline machine payment, but routes it through Stripe. A business already on Stripe can accept payments over MPP using the same PaymentIntents API it uses for human payments, and the funds settle into its normal Stripe balance, with the usual tax, fraud, reporting, and refund machinery. It pairs with Tempo, the blockchain Stripe uses for stablecoin settlement, and Stripe’s machine-payments documentation now lists Solana alongside Tempo for MPP crypto settlement, plus Stripe’s card networks for fiat. For the detail, see MPP explained.

The important thing to hold onto is how much they have in common. Both build on the same web mechanism, HTTP 402, so an agent can settle a charge inside a single request. Both target the machine-to-machine lane: agent-to-agent payments, microtransactions, and per-call billing for APIs, compute, and content. And both are real today, sitting beneath the consumer-checkout protocols rather than competing with them. The difference is not the idea; it is who sponsors it and how the money actually moves.

How they differ

Three differences matter. Sponsorship: x402 comes from Coinbase and is crypto-native; MPP comes from Stripe and Tempo and is anchored in Stripe’s existing payments stack. Settlement breadth: x402 settles in stablecoins; MPP settles in stablecoins as well as the cards, wallets, and other methods carried by Stripe’s Shared Payment Tokens, which makes it easier to fold machine payments into a business that already takes card payments. Rails: x402 settles on-chain through a facilitator the merchant does not have to operate; MPP settles through Tempo and Stripe, so the integration looks like the rest of Stripe. For how both relate to the wider money flow, see how AI agents pay.

Governance

x402 is organized through the x402 Foundation, which launched operationally under the Linux Foundation on 14 July 2026 with 40 members and a premier tier spanning Visa, Mastercard, American Express, Stripe, Adyen, Fiserv, Google, Shopify, AWS, Cloudflare, Coinbase, Circle, and Ripple. That gives it genuinely neutral, multi-party stewardship, and the protocol repository now lives at github.com/x402-foundation/x402 rather than under Coinbase.

MPP is steered by its co-authors, Tempo Labs and Stripe, who are named as the maintaining organizations on the specification repository. There is no foundation. What MPP has instead is a standards-body route: its core, defined as an HTTP authentication scheme, was submitted to the IETF on 18 March 2026 as draft-ryan-httpauth-payment with an intended status of Standards Track. Read that carefully, because MPP’s own site links to it as “IETF Specs.” The IETF Datatracker records the document as an individual Internet-Draft with no RFC stream, no working group, and no formal standing in the IETF standards process, expiring 19 September 2026. Anyone may submit an Internet-Draft; adoption by a working group is the step that has not happened. The drafts are now collected at paymentauth.org, and a second one, draft-payment-discovery-00, was submitted on 7 August 2026 by Tempo Labs and Merit Systems, covering OpenAPI-based service discovery with an intended status of Informational. It is an individual submission too. The picture is a spec family accumulating in the IETF’s document system rather than moving through the IETF’s process. The MPP specifications themselves are released under CC0 1.0, effectively the public domain, which is a more permissive posture than either protocol’s tooling license.

So the two have taken different routes to the same destination. The crypto-native standard leaned on a foundation early and now has multi-party governance in place. The provider-backed standard has stayed with its sponsors and pointed at the IETF, which, if a working group takes the draft up, would eventually deliver a more durable form of neutrality than a foundation, and which, if it does not, delivers none. As of August 2026 that question is open.

Which should you use?

Follow the settlement you need. If you want pure on-chain stablecoin settlement and a facilitator model, x402 fits, and its foundation governance may appeal if neutrality matters to you. If you want to accept machine payments alongside your existing card and wallet flows, through a single provider with familiar tooling, MPP through Stripe is the smaller lift. And because Stripe supports both, the choice is frequently not exclusive: you can pick based on whether you want stablecoin-only or mixed settlement, and revisit as the two standards mature.

FAQ

What is the difference between x402 and MPP? Both are HTTP 402-based machine settlement standards. x402 is Coinbase’s stablecoin-focused protocol, settling on-chain through a facilitator; MPP is Stripe and Tempo’s, settling in stablecoins as well as the cards, wallets, and other methods Shared Payment Tokens carry.

Do they compete? They are parallel options at the same settlement layer, targeting the same machine-to-machine use cases. But Stripe supports both, so they are not mutually exclusive.

Which should I use? x402 for pure on-chain stablecoin settlement and a crypto-native facilitator model; MPP for accepting machine payments alongside existing card flows through Stripe. Stripe supporting both means the decision often comes down to stablecoin-only versus mixed settlement.