x402 Payment Integration

Seamless micropayments for AI-powered smart contract audits.

Overview

Hexific offers two methods for professional AI-powered smart contract audits via x402 micropayments:

ZIP Upload

$0.10 USDC

• Upload your Foundry/Hardhat project
• Supports unverified & private contracts
• Full Slither + Claude analysis

Address-Based

50% CHEAPER

$0.05 USDC

• Just provide contract address
• Auto-fetches from Etherscan
• Requires verified contract

Methods Comparison

Feature	ZIP Upload	Address-Based
Price	$0.10 USDC	$0.05 USDC
API Endpoint	/ai-audit-pro	/ai-audit-address
Input	.zip file (FormData)	Contract address (JSON)
Verified Required	No	Yes
Private Contracts	Yes	No
Networks	Any EVM	Ethereum (more coming)
Best For	Pre-deployment audits	Deployed contracts

Prerequisites

Node.js & npm — Version 16.x or higher
Wallet with USDC on Base Sepolia — Get testnet USDC from Circle Faucet
Private Key — Store securely in environment variables

Installation

npm install x402-fetch viem

ZIP Upload Audit

Endpoint: POST /ai-audit-pro • Price: $0.10 USDC

When to use

Pre-deployment audits for private contracts
Projects not yet deployed on mainnet
Full Foundry/Hardhat project analysis
Contracts not verified on block explorers

Example Code

import { wrapFetchWithPayment } from "x402-fetch";
import { privateKeyToAccount } from "viem/accounts";
import fs from 'fs';

const account = privateKeyToAccount("0xYourPrivateKey");
const fetchWithPayment = wrapFetchWithPayment(fetch, account);

const zipFile = fs.readFileSync('./my-contract.zip');
const formData = new FormData();
formData.append('file', new Blob([zipFile]), 'my-contract.zip');

const response = await fetchWithPayment('https://api.hexific.com/ai-audit-pro', {
  method: 'POST',
  body: formData,
});

const result = await response.json();
console.log(result.detailed_audit);

ZIP Requirements: Max 100MB, must contain .sol files, include foundry.toml or hardhat.config.js for best results.

Address-Based Audit

Endpoint: POST /ai-audit-address • Price: $0.05 USDC

When to use

Auditing already-deployed contracts
Analyzing third-party contracts
Quick security checks on any verified contract
50% cheaper than ZIP upload!

Example Code

import { wrapFetchWithPayment } from "x402-fetch";
import { privateKeyToAccount } from "viem/accounts";

const account = privateKeyToAccount("0xYourPrivateKey");
const fetchWithPayment = wrapFetchWithPayment(fetch, account);

const response = await fetchWithPayment('https://api.hexific.com/ai-audit-address', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    contract_address: "0xdAC17F958D2ee523a2206206994597C13D831ec7",
    network: "ethereum"
  }),
});

const result = await response.json();
console.log(result.detailed_audit);

Supported Networks: Ethereum Mainnet (Base, Arbitrum, Polygon coming soon)

Resources

x402 Protocol →x402 Documentation →