---
title: "MPP | MPP machine payment protocol OpenAPI x-payment-info | Agent-Ready Check"
description: "The Machine Payment Protocol describes prices and settlement for API calls using OpenAPI extensions your existing description can carry. Pass criteria: An OpenAPI document annotates payable operations with x-payment-info."
locale: en
canonical: https://agent-ready.t0ols.com/checks/mpp/
---

# MPP

> Category: Commerce

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.

## How to implement it

Goal: 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 paid tier. The free layer gives you the diagnosis, the evidence and the specification links.

Specifications: https://mpp.dev
Implementation notes: https://agent-ready.t0ols.com/.well-known/agent-skills/mpp/SKILL.md