LupaRiel · MPP
MPP
Machine Payments Protocol (Stripe + Tempo): HTTP 402 so an agent can pay for APIs, tool calls, and content.
What it is. HTTP 402 for machine-to-machine payments on APIs, tool calls, and content. No checkout UI. Source: research/mpp.md
(150 rows, snapshot 2026-10-03, last reviewed 2026-10-11).
Who maintains it. Co-authored by Stripe and Tempo. Docs and service directory at mpp.dev.
What it is not. Stripe’s closest rail to x402. Not AP2 or ACP.
Note. If an MPP row mentions x402 in prose but is not in the x402 table, the second rail is not invented. Price and network only when the table publishes them.
Price, network, and status only when the table has them. Compare rails: x402 vs AP2 vs ACP vs MPP · PAP. Full directory (Spanish): /mpp/.
Official docs
Methodology
- How LupaRiel verifies entries
- On rail hubs, the status is the one on that rail. On the home page and the Index, the most advanced among its rails.
- Machine-readable catalog · /rieles.json
- Spanish hub + full listing · /mpp/
Protocol updates
- 2026-10-11. Three new x402 APIs also charge via MPP in the same 402: Zumpay Arc Liquidity API and wtsp.dev with the Tempo method (chainId 4217), and ProviderSignal with the Stripe method (card or Link; $0.50, Stripe's card minimum). Same pattern as dTelecom. LupaRiel re-probe 2026-10-11. Zumpay ficha · wtsp.dev ficha · ProviderSignal ficha
- 2026-10. Stripe lists MPP on Solana (USDC) in addition to Tempo (USDC.e); x402 is Base (USDC) only. First MPP-on-Solana entry in the research. Stablecoins are available to businesses in all U.S. states except New York; outside the U.S., on request in 30+ countries. The docs don't date the change (checked 2026-10-10). Stripe docs · Machine payments
- 2026-10-09. Multi-protocol seller example: dTelecom Agent Session Gateway charges for credit purchases via MPP (WWW-Authenticate: Payment challenge, tempo method, chainId 4217) and, on the same gateway, via x402. LupaRiel re-probe 2026-10-09. dTelecom ficha · x402.dtelecom.org/.well-known/x402
Protocol updates with a cited source. They are not catalog rows and do not change the snapshot.
Sample entries
- Anthropic · production · 2026-10-11
- OpenAI · production · 2026-10-11
- Browserbase · production · 2026-10-15
These names come from the research tables (snapshot 2026-10-03). LupaRiel does not invent rows, prices, networks, or statuses. The complete listing stays on the Spanish hub.