Resources

Error Codes

Code Name Description
200 OK Request successful
402 Payment Required Missing or invalid x402 payment header
413 Payload Too Large Code exceeds 100KB limit
429 Too Many Requests Rate limit exceeded (100 req/min)
500 Server Error Internal error, refund may be eligible
Refunds

If you receive a 500 error due to infrastructure failure, you may be eligible for a refund. Contact support with your job ID.

Smart Contract

All attestations are recorded on Base Sepolia:

Contract Details 
Network:     Base Sepolia
Address:     0x3Faff789460Bf79db94b0034AF7dd779C81e6BA9
Standard:    ERC-8004
Explorer:    basescan.org

View Attestations

You can query attestations directly from the contract:

Solidity Interface 
function getVerifierStats(address verifier) 
    external view 
    returns (
        uint256 total,
        uint256 successful,
        uint256 firstAttestation,
        uint256 lastAttestation
    );

function getLatestAttestation(bytes32 taskHash)
    external view
    returns (Attestation memory);

Code Examples

Calculate Task Hash (Node.js)

JavaScript 
const crypto = require('crypto');

const taskData = JSON.stringify({
  taskType: 'code-execution',
  code: 'console.log(2 + 2)',
  expectedHash: '8e9075af...',
  inputData: { expectedOutput: '4' }
});

const hash = crypto
  .createHash('sha256')
  .update(taskData)
  .digest('hex');

console.log('Task hash:', hash);

Send Payment (viem)

TypeScript 
import { createWalletClient, http, parseEther } from 'viem';
import { baseSepolia } from 'viem/chains';

const tx = await walletClient.sendTransaction({
  to: '0x75E95F6Dfb96d1aF22E2eEaAb3044cDa42b88562',
  value: parseEther('0.001')
});

// Use tx hash as X-402-Payment header
console.log('Payment:', tx);

Verify Response (Python)

Python 
import requests

headers = {
    'Content-Type': 'application/json',
    'X-402-Payment': '0x...'
}

data = {
    'taskType': 'code-execution',
    'code': 'print(2 + 2)',
    'expectedHash': '...'
}

response = requests.post(
    'https://api.workproof.run/verify',
    headers=headers,
    json=data
)

result = response.json()
print(f"Result: {result['result']}")
print(f"Attestation: {result['registryTxHash']}")

Base Sepolia Explorer

View the ValidationRegistry contract and all attestations on-chain.

View on BaseScan →

x402 Payment Protocol

Learn more about the x402 standard for agent-to-service payments.

x402.org →

Fly.io

WorkProof runs on Fly Machines for isolated, fast VM execution.

fly.io →

GitHub Repository

Open source implementation of the WorkProof protocol.

View on GitHub →