# Machine Payments Protocol (MPP)

> MPP (mpp.dev, tempoxyz/mpp-specs) — an open standard for machine-to-machine payments co-authored by Tempo and Stripe. Standardizes HTTP 402 via a 'Payment' HTTP auth scheme so any client (AI agent, app, human) can pay inside one HTTP request. Payment-method agnostic across 10 rails.
> Covers: The MPP spec repo (tempoxyz/mpp-specs, snapshot 2026-08-10, all draft-00): the core Payment HTTP auth scheme (402 challenge/response, headers, problem codes), charge & subscription intents, the discovery extension, the MCP transport extension, the Rust SDK (mpp-rs) integration angle, spec-authoring/extension points, the community ecosystem registry, and one entity page per payment method (card, EVM, Solana, Stellar, Hedera, Lightning, NEAR Intents, Stripe, Tempo, USDC) with charge/session/subscription support.
> Not covered: x402 (a separate but overlapping protocol — noted where relevant, not documented); rails without a published draft; production/mainnet deployment specifics; no XL tier yet (draft-stage).

- [LLM Wiki](/raw/mpp/README.md)
- [Machine Payments Protocol (MPP) Knowledge Base](/raw/mpp/wiki/index.md)
- [MPP Ecosystem and Registry](/raw/mpp/wiki/concepts/ecosystem.md)
- [Extending MPP (Spec Authoring)](/raw/mpp/wiki/concepts/extending-mpp.md)
- [MCP / JSON-RPC Transport Extension](/raw/mpp/wiki/concepts/mcp-transport.md)
- [MPP Overview](/raw/mpp/wiki/concepts/mpp-overview.md)
- [Payment Discovery Extension](/raw/mpp/wiki/concepts/payment-discovery.md)
- [The Payment HTTP Authentication Scheme](/raw/mpp/wiki/concepts/payment-http-auth-scheme.md)
- [Payment Intents (Charge and Subscription)](/raw/mpp/wiki/concepts/payment-intents.md)
- [Using MPP (Rust SDK Integration)](/raw/mpp/wiki/concepts/using-mpp.md)
- [Method: Card](/raw/mpp/wiki/entities/method-card.md)
- [Method: EVM](/raw/mpp/wiki/entities/method-evm.md)
- [Method: Hedera](/raw/mpp/wiki/entities/method-hedera.md)
- [Method: Lightning](/raw/mpp/wiki/entities/method-lightning.md)
- [Method: NEAR Intents](/raw/mpp/wiki/entities/method-near-intents.md)
- [Method: Solana](/raw/mpp/wiki/entities/method-solana.md)
- [Method: Stellar](/raw/mpp/wiki/entities/method-stellar.md)
- [Method: Stripe](/raw/mpp/wiki/entities/method-stripe.md)
- [Method: Tempo](/raw/mpp/wiki/entities/method-tempo.md)
- [Method: USDC](/raw/mpp/wiki/entities/method-usdc.md)
- [MPP Methods Catalog](/raw/mpp/wiki/entities/methods-catalog.md)
- [Change Log](/raw/mpp/wiki/log.md)