The First x402 Payment API

Pay per request with USDC. No subscriptions, no credit cards. Just instant micropayments for AI agents and developers.

View Documentation Demo Guide Explore Endpoints

Why x402?

⚡ Instant Payments

Pay per request, no subscriptions. Perfect for AI agents making autonomous payments.

💰 Micropayments

Pay as little as $0.004 per request. QR code endpoint free. No minimums, no commitments.

🤖 AI Agent Ready

Native x402 support means AI agents can pay automatically without human intervention.

🌐 No Account Required

Just pay and use. No registration, no credit cards, no KYC.

API Endpoints

Market Data

GET /v1/market/price/:symbol
$0.005
GET /v1/market/ohlcv/:symbol
$0.005
GET /v1/market/trending
$0.002

AI Tools

POST /v1/ai/summarize
$0.01
POST /v1/ai/sentiment
$0.01
POST /v1/ai/translate
$0.02
POST /v1/ai/code-review
$0.05

Crypto Analytics

GET /v1/crypto/wallet-score/:address
$0.05
GET /v1/crypto/token-analysis/:address
$0.10
GET /v1/crypto/whale-alerts
$0.02

Utilities

POST /v1/util/qr-code
$0.005
POST /v1/util/screenshot
$0.02
POST /v1/util/pdf-generate
$0.03

Example Usage

// 1. Make request (receives 402)
const response = await fetch('https://api.asterpay.io/v1/market/price/BTC');
// Note: Replace with your actual API URL when deployed

// 2. Parse 402 response
const payment = await response.json();
// {
//   "x402Version": 1,
//   "scheme": "exact",
//   "network": "base-sepolia",
//   "payTo": "0x...",
//   "maxAmountRequired": "5000", // $0.005 in USDC (6 decimals)
//   ...
// }

// 3. Create payment transaction
const tx = await wallet.sendTransaction({
  to: payment.payTo,
  value: payment.maxAmountRequired,
  // ... transaction details
});

// 4. Retry with payment proof
const paidResponse = await fetch('https://api.asterpay.io/v1/market/price/BTC', {
  headers: {
    'X-PAYMENT': JSON.stringify({
      scheme: 'exact',
      network: 'base-sepolia',
      payload: Buffer.from(JSON.stringify({
        txHash: tx.hash,
        amount: payment.maxAmountRequired,
        timestamp: new Date().toISOString()
      })).toString('base64')
    })
  }
});

// 5. Get data
const data = await paidResponse.json();