Machine Payments Protocol (MPP)

The open HTTP 402 standard for machine-to-machine payments. AI agents pay per API call, tool use, or content — in the same HTTP request. No keys. No accounts. Payment = authentication.

Launched mid-March 2026 by Tempo + Stripe. Already powering real agentic commerce across the web.

What is MPP?

MPP is an open, payment-method-agnostic protocol that standardizes the long-ignored HTTP 402 Payment Required status code with a formal IETF-proposed authentication scheme (paymentauth.org).

One HTTP call does everything: discover → negotiate price → pay → receive result. Perfect for AI agents that need to spend money autonomously.

How It Works (Step-by-Step)

  1. Agent sends normal request (e.g. GET /itinerary)
  2. Server replies 402 Payment Required + WWW-Authenticate: Payment ... challenge (price, method, etc.)
  3. Agent pays instantly (Tempo USDC, Stripe card, Lightning, etc.)
  4. Agent retries request with Authorization: Payment ... proof
  5. Server verifies & returns result + receipt

Entire flow: sub-second settlement. Works with any backend (Express, Hono, Cloudflare, etc.).

Key Features & Benefits

  • ✅ Payment = auth (no API keys ever)
  • ✅ Works for agents AND humans
  • ✅ Two intents: charge (one-time) or session (streaming/pay-per-token)
  • ✅ Middleware for instant monetization of existing APIs
  • ✅ Official SDKs: TypeScript (mppx), Python (pympp), Rust (mpp-rs)
  • ✅ Open source & extensible — add your own payment rails

Supported Payment Methods

Tempo (Stablecoins)

USDC & other stables on Tempo blockchain. Sub-second finality.

Docs →

Stripe (Cards & Wallets)

Full Stripe stack via Shared Payment Tokens. Human-friendly.

Docs →

Lightning (Bitcoin)

Native BTC Lightning payments.

Docs →

Real-World Use Cases (Live Right Now)

1. Goplan.me — AI Travel Agent

Pay $1 USDC via MPP → get a full personalized 1-14 day itinerary (Gemini-powered). No signup, no key. Pure payment = access.

Try live →

@GoplanDotMe on X

2. dTelecom — Voice & Video for Agents

Real-time calls, meetings, STT/TTS. Agents pay per minute/second via MPP + Tempo. Zero accounts or keys.

Visit dTelecom →

@dtelecom on X

3. Ask-Tom API — RAG Payments Expert

$1 per query on Tom Noyes’ full payments blog corpus. ChatGPT/Anthropic-accessible. Full MPP + Stripe integration with blog post breakdown.

Try Ask-Tom →

@noyesclt on X

4. Parallel & fal.ai Demos (Official)

Built-in MPP examples on mpp.dev: summarize articles or generate images — pay with Tempo or Stripe in one click.

Try the demos →

5. Open-Source Proxies & Gateways

mppx-proxy, mpp-solana, and Lightning-stack integrations let any existing API add MPP in minutes without rewriting code.

Search “mppx-proxy” on GitHub/X

Getting Started as a Developer

Quickest way:

npm install mppx
# or
pip install pympp

Add middleware to your existing Express/Hono/Elysia app in ~10 lines. Full guides:

Resources & Links

  • Official Site: mpp.dev (live demos + CLI)
  • IETF Spec: paymentauth.org
  • Tempo: tempo.xyz
  • Follow the project: @mpp on X
  • Early buzz: Search “MPP” or “Machine Payments Protocol” on X (hundreds of threads in first 72 hours)

The missing piece for true agentic commerce is here.
Build it. Charge for it. Let agents pay instantly.