Use CasesAPI Monetization

API Monetization

Charge per-request fees for your API endpoints with simple middleware. No payment gateway, no subscriptions - just HTTP headers.

Overview

T402 makes API monetization simple:

  • Per-request pricing: Charge exactly what each endpoint is worth
  • Instant settlement: Receive USDT immediately, no invoicing
  • Zero chargeback risk: Blockchain payments are final
  • Simple integration: Add middleware to existing APIs

Quick Start

1. Install Dependencies

pnpm add @t402/express @t402/evm

2. Add Payment Middleware

import express from 'express'
import { paymentMiddleware } from '@t402/express'
import { ExactEvmScheme } from '@t402/evm'
 
const app = express()
 
// Configure pricing per endpoint
app.use(paymentMiddleware({
  'GET /api/basic': {
    price: '$0.001',
    network: 'eip155:8453',
    payTo: process.env.WALLET_ADDRESS,
    description: 'Basic API access'
  },
  'GET /api/premium': {
    price: '$0.01',
    network: 'eip155:8453',
    payTo: process.env.WALLET_ADDRESS,
    description: 'Premium API access'
  },
  'POST /api/compute': {
    price: '$0.10',
    network: 'eip155:8453',
    payTo: process.env.WALLET_ADDRESS,
    description: 'Heavy computation'
  }
}))
 
// Your existing routes work as normal
app.get('/api/basic', (req, res) => {
  res.json({ data: 'Basic response' })
})
 
app.get('/api/premium', (req, res) => {
  res.json({ data: 'Premium response with more details' })
})
 
app.listen(3000)

Pricing Strategies

Fixed Per-Request

Simple, predictable pricing:

'GET /api/weather': {
  price: '$0.001',
  // ...
}

Dynamic Pricing

Price based on request parameters:

import { paymentMiddleware, PriceResolver } from '@t402/express'
 
const dynamicPricing: PriceResolver = (req) => {
  const complexity = req.query.complexity || 'low'
  const prices = {
    low: '$0.01',
    medium: '$0.05',
    high: '$0.25'
  }
  return prices[complexity] || prices.low
}
 
app.use(paymentMiddleware({
  'POST /api/analyze': {
    price: dynamicPricing,
    network: 'eip155:8453',
    payTo: process.env.WALLET_ADDRESS
  }
}))

Tiered Pricing

Different prices for different tiers:

'GET /api/data': {
  price: '$0.001', // Default tier
  tiers: {
    basic: '$0.001',
    pro: '$0.0005',    // 50% discount
    enterprise: '$0'    // Free for enterprise
  }
}

Framework Integrations

Express.js

import { paymentMiddleware } from '@t402/express'
app.use(paymentMiddleware(config))

Next.js API Routes

import { withPayment } from '@t402/next'
 
export default withPayment(handler, {
  price: '$0.01',
  network: 'eip155:8453',
  payTo: process.env.WALLET_ADDRESS
})

Hono

import { paymentMiddleware } from '@t402/hono'
app.use('/api/*', paymentMiddleware(config))

Multi-Network Support

Accept payments on multiple networks:

'GET /api/data': {
  price: '$0.01',
  networks: ['eip155:8453', 'eip155:42161', 'ton:-239'],
  payTo: {
    'eip155:8453': '0xBaseAddress...',
    'eip155:42161': '0xArbitrumAddress...',
    'ton:-239': 'UQTonAddress...'
  }
}

Monitoring & Analytics

Track Payments

import { paymentMiddleware, PaymentEvent } from '@t402/express'
 
app.use(paymentMiddleware(config, {
  onPayment: (event: PaymentEvent) => {
    console.log(`Payment received: ${event.amount} ${event.asset}`)
    // Log to your analytics service
    analytics.track('payment', {
      endpoint: event.path,
      amount: event.amount,
      network: event.network,
      txHash: event.txHash
    })
  }
}))

Facilitator Dashboard

Monitor payments via the facilitator dashboard:

https://grafana.facilitator.t402.io

Best Practices

Start Small: Begin with low prices ($0.001) and adjust based on demand.

  1. Clear pricing: Show prices in API documentation
  2. Reasonable limits: Set appropriate rate limits alongside payments
  3. Error handling: Return clear error messages for failed payments
  4. Testing: Use testnets during development

Example: Weather API

Complete example of a monetized weather API:

import express from 'express'
import { paymentMiddleware } from '@t402/express'
 
const app = express()
 
app.use(paymentMiddleware({
  'GET /weather/current': {
    price: '$0.001',
    network: 'eip155:8453',
    payTo: process.env.WALLET_ADDRESS,
    description: 'Current weather data'
  },
  'GET /weather/forecast': {
    price: '$0.01',
    network: 'eip155:8453',
    payTo: process.env.WALLET_ADDRESS,
    description: '7-day weather forecast'
  },
  'GET /weather/historical': {
    price: '$0.05',
    network: 'eip155:8453',
    payTo: process.env.WALLET_ADDRESS,
    description: 'Historical weather data'
  }
}))
 
app.get('/weather/current', async (req, res) => {
  const { city } = req.query
  // Fetch weather data...
  res.json({ city, temp: 22, condition: 'sunny' })
})
 
app.listen(3000, () => {
  console.log('Weather API running on port 3000')
})

Next Steps

AI Agent PaymentsPremium Content