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Protocols · Stripe machine payments

What is Stripe machine payments, and what does it actually do?

Stripe’s rails for software buyers: agents pay in stablecoins or by card, through payment credentials scoped to a single agent. One of the four payment rails this site covers — same template, same depth as its peers. Described, never ranked.

What is it?

Stripe machine payments is card infrastructure re-cut for software buyers: Stripe’s rails for agent purchases, including payment credentials scoped to a single agent. The name covers a family of pieces, not one product — an open payment protocol, scoped payment tokens, virtual cards for agents, and a checkout specification.

The anchor is the Machine Payments Protocol (MPP), an open standard for machine-to-machine payments, co-authored by Tempo and Stripe and announced 2026-03-18. MPP lets any service charge software per request, over plain HTTP. A business on Stripe accepts these payments through its existing integration — in stablecoins, or in cards and buy-now-pay-later through Shared Payment Tokens (SPTs): grants scoped to one business, limited by time or amount, and revocable at any time.

A sibling specification handles the human-present case: ACP (Agentic Commerce Protocol), co-developed with OpenAI, lets a person complete a purchase inside a chat — the checkout comes to the conversation. Stripe’s docs draw the line plainly: sell through agents with ACP or UCP; accept machine payments with MPP or x402.

Who is behind it?

Stripe, the payments company — with different co-authors per piece. MPP is co-authored by Tempo and Stripe; its specification documents are public domain (CC0 1.0), maintained in a public repository, with the core specification published as an IETF draft. ACP was co-developed with OpenAI and announced 2025-09-29.

The specifications are open; the rails are Stripe’s. Payments accepted this way land in a business’s existing Stripe balance and run through Stripe’s standard machinery — fraud screening, refunds, reporting, accounting integrations. Stripe’s machine-payments stack supports x402 alongside MPP.

How does a payment flow?

The MPP flow, in five steps:

  1. An agent requests a resource — an API call, a dataset, a browser session — from any HTTP-addressable endpoint, including MCP servers.
  2. The server answers HTTP 402 “Payment Required”, with a challenge stating what payment it needs.
  3. The agent fulfills the payment by one of the offered methods: a stablecoin transfer, or a card through a Shared Payment Token.
  4. The agent retries the request, now carrying a credential that proves payment. The server validates it and serves the resource.
  5. For a seller on Stripe, the payment appears in the Dashboard like any other transaction and settles into its existing balance, in its default currency. Refunds work through the standard Refunds API.

Where does the agent’s money come from?

Two scoped instruments, both built so the agent never holds a person’s raw card details. A Shared Payment Token is a grant to use a buyer’s saved payment method — scoped to a specific business, capped by time or amount, revocable at any time. A virtual card from Stripe’s Issuing for agents is issued per agent, or per purchase, with spending caps and merchant controls set before the agent can spend.

Link’s wallet for agents, launched 2026-04-29, builds on both: per Stripe’s announcement, each spend request today waits for the person’s approval before any credential reaches the agent — a human-in-the-loop by default.

Where does it stand today?

Live. MPP launched 2026-03-18 with named businesses already charging agents — for API calls, browser sessions, even sandwiches. Shared Payment Tokens have been in use since 2025-10-07. ACP has powered Instant Checkout in ChatGPT since 2025-09-29. Issuing for agents and Link’s wallet for agents launched 2026-04-29.

As of 2026-09-02, Stripe’s machine-payments docs list stablecoin settlement over MPP on the Tempo and Solana networks, and over x402 on the Base network — with USDC the listed currency. The stated minimum amounts: 50 cents for a card payment through an SPT, and one cent for a stablecoin payment — micropayment territory. Per the same docs, SPTs are available to US businesses; stablecoin payments to US businesses outside New York, and in other countries by request.

Usage and volume figures: not yet published by Stripe. These payments run on Stripe’s own rails, and Stripe has released no settlement data for them, so no usage numbers appear on this page. Where a backer publishes nothing on a point, we say so instead of guessing — the bar any number must clear is in the methodology.

Where are the primary sources?

Everything on this page traces to Stripe’s own documents, all checked on 2026-09-02:

What changed on this page?