x402 Adapter

What is x402?

x402 is Coinbase’s open protocol for HTTP-native payments. When an HTTP server returns a 402 Payment Required response with payment details, an x402-capable client pays and retries. Perfect for AI-to-AI service charging.

Usage

import { probeX402Endpoint, executeAgentPayment } from '@pqsafe/agent-pay'

// Discover payment requirements
const requirements = await probeX402Endpoint('https://api.aiservice.xyz/analyze')

console.log(requirements.maxAmountRequired) // e.g. 0.001 (USDC)
console.log(requirements.network)           // 'base-mainnet'

// Create envelope scoped to this endpoint
const envelope = createSpendEnvelope({
  maxAmount: 1,
  currency: 'USDC',
  allowedRails: ['x402'],
  allowedRecipients: ['api.aiservice.xyz'],
  validUntil: new Date(Date.now() + 300_000), // 5 min
  agentId: 'my-agent',
})

const signed = createSignedEnvelope(envelope, secretKey)

// Execute — handles 402 dance automatically
const result = await executeAgentPayment(signed, {
  recipient: 'api.aiservice.xyz',
  amount: 0.001,
  rail: 'x402',
})

Environment

X402_FACILITATOR_URL=https://x402.org/facilitator
WALLET_PRIVATE_KEY=0x...
BASE_RPC_URL=https://mainnet.base.org

→ x402 Rail