MPP Project Setup

Before writing code

Fetch live docs:

1. Fetch https://www.npmjs.com/package/mppx for the latest mppx SDK version, installation, and API surface
2. Web-search site:github.com stripe-samples machine-payments for the official sample project structure
3. Fetch https://docs.stripe.com/payments/machine for Stripe machine payments setup requirements
4. Web-search site:mpp.dev overview for the current protocol overview and getting started guide

What This Skill Does

Scaffolds a new MPP project for monetizing HTTP services with machine payments:

1. Detect language/framework — TypeScript (Hono/Express/Next.js/Elysia), Python (FastAPI/Flask), or Rust
2. Install SDK — npm install mppx (TypeScript), pip install pympp (Python), or check mpp.dev for the Rust crate
3. Create configuration — Environment variables for secret key, payment method settings, Stripe keys
4. Set up server middleware — Mppx.create() with payment method configuration
5. Create a paid endpoint — Basic route protected by mppx.charge() middleware
6. Add service discovery — GET /openapi.json with x-payment-info extensions
7. Set up client (optional) — mppx.fetch() for consuming paid APIs

Environment Configuration

These must be externalized (env vars or config file):

• MPP_SECRET_KEY — 32-byte hex key for HMAC challenge binding (generate with openssl rand -hex 32)
• STRIPE_SECRET_KEY — If using Stripe payment method
• TEMPO_RECIPIENT_ADDRESS — Wallet address for receiving Tempo payments
• TEMPO_CHAIN_ID — 4217 for Tempo mainnet
• TEMPO_USDC_CONTRACT — 0x20c000000000000000000000b9537d11c60e8b50 for USDC on Tempo

Project Structure Pattern

my-mpp-service/
├── src/
│   ├── index.ts              # Server entry point with Mppx middleware
│   ├── routes/
│   │   ├── paid.ts           # Payment-protected endpoints
│   │   └── free.ts           # Free/health endpoints
│   ├── config.ts             # MPP and payment method configuration
│   └── openapi.ts            # Service discovery endpoint
├── .env                      # Secrets (MPP_SECRET_KEY, STRIPE_SECRET_KEY)
├── package.json
├── tsconfig.json
└── tests/
    └── payment.test.ts

Key Setup Decisions

• Payment method — Tempo (crypto, sub-second), Stripe (cards via SPT), Lightning, or multiple
• Payment intent — Charge (one-time per request) or Session (streaming micropayments)
• Framework — Hono (recommended, lightweight), Express, Next.js, or Elysia
• Pricing model — Fixed per-request, dynamic based on payload, or session-based streaming

Quick Start Pattern (Hono + Tempo)

import { Hono } from 'hono';
import { Mppx, tempo } from 'mppx/server';

const mppx = Mppx.create({
  secretKey: process.env.MPP_SECRET_KEY,
  methods: [
    tempo.charge({
      chainId: 4217,
      currency: '0x20C000000000000000000000b9537d11c60E8b50',
      recipient: process.env.TEMPO_RECIPIENT_ADDRESS,
    }),
  ],
});

const app = new Hono();
app.get('/api/data', mppx.charge({ amount: '100' }), (c) => {
  return c.json({ data: 'premium content' });
});

Fetch the latest mppx README and Stripe machine payments docs for exact SDK API, current payment method configuration options, and framework-specific setup before scaffolding.