name: x402-paywall description: "Enables OpenClaw agents to monetize premium content and services using HTTP 402 Payment Required protocol with USDC micropayments on Base." version: 1.0.0 metadata: openclaw: emoji: "💳" requires: network: true filesystem: false permissions: - "network.http.client" - "network.http.server" - "blockchain.base.read" - "blockchain.base.write" inputs:

• name: "content_request" type: "string" description: "The premium content or service being requested"
• name: "requester_wallet" type: "string" description: "Ethereum address of the requesting agent"
• name: "payment_amount" type: "number" description: "USDC amount in wei (optional, auto-calculated if not provided)" outputs:
• name: "payment_required_response" type: "object" description: "HTTP 402 response with payment details"
• name: "protected_content" type: "string" description: "The requested content after successful payment verification" examples:
• description: "Request premium Base ecosystem analysis" input: | { "content_request": "Latest Base DeFi protocol analysis with TVL trends", "requester_wallet": "0x742d35Cc6634C0532925a3b8D43c1430C8b1fd37" } output: | { "status": 402, "headers": { "PAYMENT-REQUIRED": "<base64-encoded payment info>" }, "payment_info": { "amount": "5000000", "currency": "0x036CbD53842c5426634e7929541eC2318f3dCF7e", "payment_id": "req_base_analysis_1707349920" } }

x402 Paywall Skill for OpenClaw

Enable autonomous agent-to-agent commerce using HTTP 402 Payment Required with USDC micropayments on Base L2.

Overview

This skill implements the x402 protocol — a standard where HTTP 402 responses carry structured payment requirements that agents can automatically fulfill using onchain USDC transfers. It includes:

• X402Server — Serve premium content behind a USDC paywall
• X402Client — Automatically detect, pay, and retry 402 responses
• PaymentFacilitator — Smart contract for trustless payment verification on Base Sepolia

How It Works

1. Server Returns 402 Payment Required

When an agent requests premium content without payment:

HTTP/1.1 402 Payment Required
PAYMENT-REQUIRED: base64({
  "amount": "5000000",
  "currency": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
  "acceptedMethods": ["facilitator"],
  "expiry": 1707353520,
  "paymentId": "req_analysis_1707349920",
  "payee": "0xServerWallet...",
  "facilitator": "0xFacilitatorContract..."
})

2. Client Pays via Facilitator Contract

The client agent:

1. Approves USDC spending on the facilitator contract
2. Calls submitPayment(paymentId, payee, amount) on-chain
3. Retries the original request with a PAYMENT-SIGNATURE header containing the tx hash

3. Server Verifies and Serves Content

The server:

1. Calls verifyPayment(paymentId, payer, amount) on the facilitator
2. If valid, serves the premium content with HTTP 200
3. Calls settlePayment(paymentId) and withdraw() to collect funds

Usage

Serving Paid Content

const { X402Server } = require('./src/x402-client');
const http = require('http');

const server = new X402Server({
  facilitatorAddress: '0x...', // Deployed PaymentFacilitator
  payeeAddress: '0x...',       // Your wallet
  rpcUrl: 'https://sepolia.base.org'
});

// Price content at 5 USDC
server.addContent('/analysis/defi', async () => {
  return { title: 'DeFi Report', data: { tvl: '$2.4B' } };
}, 5.0);

http.createServer((req, res) => server.handleRequest(req, res)).listen(3402);

Consuming Paid Content

const { X402Client } = require('./src/x402-client');
const { ethers } = require('ethers');

const client = new X402Client({
  wallet: new ethers.Wallet(privateKey),
  facilitatorAddress: '0x...',
  rpcUrl: 'https://sepolia.base.org'
});

// Automatically handles 402 → approve → pay → retry
const response = await client.request('http://agent-server:3402/analysis/defi');
console.log(response.data); // Premium content

Base Sepolia Integration

| Resource | Value | |----------|-------| | USDC Token | 0x036CbD53842c5426634e7929541eC2318f3dCF7e | | RPC | https://sepolia.base.org | | Chain ID | 84532 | | Explorer | https://sepolia.basescan.org |

Getting Testnet Funds

1. ETH (for gas): https://www.alchemy.com/faucets/base-sepolia
2. USDC: https://faucet.circle.com (select Base Sepolia)

Smart Contract

The PaymentFacilitator contract (contracts/PaymentFacilitator.sol) handles:

• Payment escrow — USDC locked until settled
• Payment verification — On-chain proof that payment occurred
• Settlement — Payee collects after content delivery
• Withdrawal — Payee withdraws accumulated balance
• Expiry — Payments expire after 1 hour if unsettled

Compiled artifacts are in build/.

Installation

git clone https://github.com/BAiSEDagent/x402-paywall-skill.git
cd x402-paywall-skill
npm install

For OpenClaw integration:

cp -r x402-paywall-skill ~/.openclaw/skills/

Testing

npm test  # Runs 18 integration tests

Deployment

node scripts/deploy.js all      # Deploy contract + demo payment
node scripts/deploy.js deploy   # Deploy contract only
node scripts/deploy.js pay      # Demo payment on existing deployment
node scripts/deploy.js balance  # Check wallet balances