MPP

live

Machine Payments Protocol (MPP)

by Stripe, Tempo· launched 2026-03verified 2026-10-26

At a glance

Layer
execution
Category
hybrid
Rails
cards, stablecoins, USDC, Solana
Settlement
Settles through Stripe (PaymentIntents), across card and stablecoin rails; stablecoin settlement via the Tempo blockchain and Solana.
Reversible
Yes
Human in loop
optional
D2C fit
moderate
B2B fit
strong

An open, internet-native protocol for machine and agent payments, co-authored by Stripe and Tempo. Spans both card (via Shared Payment Tokens) and stablecoin rails (Tempo and Solana), settling through Stripe's existing infrastructure. The spec is open at mpp.dev. Generally available per the Stripe changelog: SPTs available in all US states and internationally; stablecoin payments in 30+ countries. October 2026 added session-based streaming payments and dynamic pricing (public preview).

How it works

MPP is an open standard co-authored by Stripe and Tempo that lets agents pay for APIs and services programmatically without a checkout UI.

  • 402 challenge flow. When an agent requests a resource, the service returns an HTTP 402 response with payment details. The agent authorizes the payment, retries the request, and receives the resource with a receipt.
  • Rail coverage. MPP spans card and stablecoin rails. Cards are handled via Shared Payment Tokens (SPTs) — scoped grants that let an agent use a customer's payment method with usage and expiration limits. Stablecoin payments settle via the Tempo blockchain and Solana (USDC). Stripe's machine-payments surface also supports x402 for stablecoin-only flows on Base.
  • Payment shapes. Covers one-shot, recurring, and streaming payments, so an agent can pay once or maintain ongoing/metered obligations. Session-based payments (October 2026, public preview) let agents pre-authorize a maximum and pay per unit of work (tokens, seconds, rows) in sub-cent increments with periodic settlement.
  • Settlement. Flows settle through Stripe PaymentIntents, which means agent payments reuse Stripe's reconciliation, reporting, and (for card rails) dispute handling.

The specification is open at mpp.dev. MPP is generally available per the Stripe changelog: SPTs are available in all US states and internationally, stablecoin payments in 30+ countries. Dynamic pricing and session-based streaming payments shipped in October 2026 as public previews.

Tradeoffs

  • Reversibility is mixed: card-rail payments retain dispute/refund rights, but stablecoin settlement does not — a single 'reversible' flag over-simplifies, so confirm per rail.
  • Settling through Stripe implies operating within Stripe's account, availability, and compliance model rather than a permissionless one.
  • Session-based and dynamic pricing features are still in public preview; integrations should track Stripe's changelog for interface changes.

Security & limitations

  • Agent-initiated recurring/streaming payments require robust scoping and revocation to prevent runaway or manipulated charges.
  • Where MPP bridges to stablecoin/x402 flows, the non-reversibility and custody considerations of on-chain settlement apply to that leg.
  • Shared Payment Tokens carry scoped card access; token leakage or insufficient scope constraints could enable unauthorized charges.

See sources below. Documented for commentary and identification only.

Fits together with

  • x402 — x402 Payment Protocol

Deployments using MPP

  • Stripe Machine Payments

    Stripe

    B2Blive

    Stripe's production machine-payments surface: accepts agent payments via MPP (card + stablecoin, one-shot through recurring/streaming) and also supports x402 for stablecoin-only flows, settling through Stripe PaymentIntents. Stablecoin settlement on Tempo and Solana (USDC); x402 on Base (USDC). SPTs available in the US, Canada, and select European countries; stablecoin payments in 30+ countries.

    Chains
    Tempo, Base, Solana
    Launched
    2026-03
    verified 2026-10-26source

Sources