Payment lifecycle event hooks in Mppx.create()

[starc007]

Feature Request

Add an event/hook system to Mppx.create() so payment events can be handled centrally instead of wrapping each route handler manually.

Problem

Right now there's no centralized way to track payments across routes. If you want analytics, logging, or alerting, you have to manually add tracking code inside every route handler:

app.get('/api/data', mppx.charge({ amount: '0.01' }), async (c) => {
  await db.insert({ event: 'payment', amount: '0.01', ... }) // manual per route
  return c.json({ data: '...' })
})

This doesn't scale for services with many endpoints, and proxy operators (mppx/proxy) have zero payment visibility.

Suggested API

An on option in Mppx.create():

const mppx = Mppx.create({
  methods: [tempo({ ... })],
  on: {
    'charge.received': (receipt, request) => { /* analytics, logging */ },
    'charge.failed': (error, challenge) => { /* alerting */ },
    'session.opened': (session) => { /* monitoring */ },
    'session.settled': (session, receipt) => { /* reconciliation */ },
    'session.closed': (session, refund) => { /* cleanup */ },
  },
})

Use Cases

• Analytics — track revenue per endpoint, per method, over time
• Monitoring — alert on failed payments, unusual patterns
• Reconciliation — match on-chain settlements to business events
• Proxy operators — centralized payment visibility across multiple upstream services

[brendanjryan]

Thank you for suggesting this! Agree on the direction, but not sure on the shape of using raw strings for event handler names.

We are thinking about this right now and I will get back to you with a proposal 🙇

[starc007]

yeah raw strings were just to show the direction. thinking out loud here - couple of approaches:

1. simple on handler

Mppx.create({
methods: [tempo({ ... })],
on: (event) => {
 // event.type, event.amount, event.method, event.route, etc.
  },
})

2. plugin system
   users create fully customizable plugins. plugins could observe events, intercept challenges, modify pricing, block bad actors - whatever they need. later people can build and share reusable plugins like auth, rate limiting, analytics, etc. and stack multiple together.

just my thoughts here, looking forward to your proposal