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MPP · rolling out

MPP payments, alongside x402.

MPP, the Machine Payments Protocol, is a challenge-and-credential payment protocol: your endpoint answers with a standard HTTP challenge, the agent presents a payment credential, and the charge settles - card or chain. Nevermined supports it as a first-class protocol next to x402, aligned with the emerging AP2 / agentic-commerce standards.

HTTP challenge/credential handshake (WWW-Authenticate: Payment)
Card and Tempo-chain settlement rails (USDC.e and EURC.e)
One SDK, one dashboard - the same as x402
MPP challengeRFC 7235
GET
/api/resource
agent requests a paid resource
402
WWW-Authenticate: Payment
server issues a payment challenge
GET
Authorization: Payment <cred>
agent retries with a credential
200
Payment-Receipt · settled ✓
verified, settled, receipt returned
How it works

Four HTTP round-trips. No sidecars.

MPP extends RFC 7235 with a "Payment" authentication scheme, so the whole flow lives inside standard HTTP headers - no extra services to run.

1

Agent sends request

A standard HTTP call to a paid endpoint. No API key, no pre-negotiation.

2

Server responds 402

An RFC 7235 “Payment” challenge with the accepted methods, price, and network.

3

Agent presents credential

The payment library selects a method, builds a credential, and retries the request.

4

Resource + receipt

The server verifies, settles, and returns the resource with a payment receipt.

Nevermined + MPP

Implemented on the rails, rolling out to the SDK.

MPP settlement is built on the Nevermined backend today - the challenge, verify, and settle path runs on the Tempo and card rails, settling in USDC.e or EURC.e on Tempo. SDK support lands next, and when it does you reach MPP the same way you reach x402: same client, same dashboard, same analytics.

One gateway, many protocols

The Router dispatches x402 and MPP through a single handler interface and detects which a merchant speaks off its 402 header.

Card and chain settlement

MPP settles via delegated cards or a native Tempo-chain transaction in USDC.e or EURC.e. Combined with x402, every rail your agents need is covered.

Same developer experience

When MPP reaches the SDK it abstracts away just like x402 - the same APIs and the same observability, nothing new to learn.

Protocol-agnostic

One integration. Both protocols.

Point your agents at any paid endpoint and Nevermined detects the standard it speaks - x402 today, MPP alongside it - then verifies and settles it the same way. Whatever standard wins, your agents can already talk, trade, and trust.

MPPRolling out

Settles across card and Tempo rails.

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x402Live

Settles across crypto and card rails.

Explore x402
Runs onTempoStripeRFC 7235AP2Compare with x402 →
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Ready for agentic payments?

Want early access to MPP with Nevermined? Get in touch and we will bring you in.