Commerce

MPP

The Machine Payment Protocol describes prices and settlement for API calls using OpenAPI extensions your existing description can carry.

Why it matters

If you already publish OpenAPI, adding payment metadata is a small step to being pay-per-call.

Pass criteria

An OpenAPI document annotates payable operations with x-payment-info.

What the scanner records
Every request the check makes is recorded (URL, method, response status, relevant headers and a body preview) and shown under the check in your results.

How to implement it

Support MPP (Machine Payment Protocol) for agent-native HTTP payments

An OpenAPI document annotates payable operations with x-payment-info.

The step-by-step implementation prompt is part of the Pro plan.

See plans

mpp.dev SKILL.md

Scan your site

See whether this check passes on your domain, along with the other 21.

Run a scan

Related checks

x402

Payable routes answer HTTP 402 with x402 requirements, or a discovery document is published.

UCP

/.well-known/ucp declares protocol_version and at least one service.

ACP

/.well-known/acp.json declares protocol.name, api_base_url, transports and capabilities.services.

AP2

The A2A Agent Card advertises an AP2 extension with role information.