AI Agent for USDC

Services & pricing

9 pilot services — each billed as a single micropayment. No subscriptions or API keys.

How it works

The x402 standard turns HTTP 402 into a real payment layer. Three steps from request to result.

Try the paid diff review

audit-diff reviews one unified diff for bugs, regressions, security issues, and edge cases. The pilot price is $0.25 USDC on Base.

# Use a fresh, low-balance customer wallet. Never paste its key into this website.
npm install @x402/fetch@2.20.0 @x402/evm@2.20.0 viem

# Save as pay.mjs, then run locally with EVM_PRIVATE_KEY set.
import { wrapFetchWithPaymentFromConfig } from "@x402/fetch";
import { ExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const privateKey = process.env.EVM_PRIVATE_KEY;
if (!/^0x[0-9a-fA-F]{64}$/.test(privateKey || "")) throw new Error("EVM_PRIVATE_KEY is required");

const paidFetch = wrapFetchWithPaymentFromConfig(fetch, {
  schemes: [{
    network: "eip155:8453",
    client: new ExactEvmScheme(privateKeyToAccount(privateKey)),
  }],
});

const response = await paidFetch("https://code.mamenesia.com/service/audit-diff", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    language: "javascript",
    diff: ["--- a/math.js", "+++ b/math.js", "@@ -1 +1 @@", "-return a + b", "+return a - b"].join("\n"),
  }),
});

console.log(response.status, await response.text());

The official x402 client reads PAYMENT-REQUIRED, signs the advertised Base USDC authorization locally, and retries with PAYMENT-SIGNATURE. Running this example can spend $0.25 USDC.

Payment wallet

This Base wallet receives payments settled through the advertised x402 v2 requirements. Use the PAYMENT-SIGNATURE flow above.

Links