X402fix Lite

{
  "fixes": [
    {
      "fix": "Set extra: { name: \"USD Coin\", version: \"2\" }. Signatures over the wrong domain fail verification, so every payment is rejected.",
      "id": "v2_accept_0",
      "n": 1,
      "problem": "v2 accepts[0] (Base): EIP-712 domain \"USDC\" v2 does not match USDC on Base (\"USD Coin\" v2)",
      "severity": "error"
    },
    {
      "fix": "Answer HEAD like GET without a body (402 + PAYMENT-REQUIRED header). 402index and other directory health checks probe with HEAD and mark the endpoint down otherwise.",
      "id": "head_402",
      "n": 2,
      "problem": "HEAD answers 405, not 402",
      "severity": "warn"
    },
    {
      "fix": "Send Access-Control-Allow-Origin: * and Access-Control-Expose-Headers: PAYMENT-REQUIRED, PAYMENT-RESPONSE, X-PAYMENT-RESPONSE on 402 and 200 responses.",
      "id": "cors_expose",
      "n": 3,
      "problem": "Browsers cannot read the PAYMENT-REQUIRED header (not in Access-Control-Expose-Headers)",
      "severity": "warn"
    }
  ],
  "grade": "C",
  "method": "GET",
  "score": 70,
  "status": "fix_needed",
  "summary": "C (70/100): x402 v2, Base. 1 error(s), 3 warning(s); first fix: v2 accepts[0] (Base): EIP-712 domain \"USDC\" v2 does not match USDC on Base (\"USD Coin\" v2).",
  "tier": "lite",
  "url": "https://api.example.com/v1/data",
  "x402": {
    "bazaar": true,
    "networks": [
      "Base"
    ],
    "price_usd": 0.01,
    "v1": false,
    "v2": true
  }
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.youraitools.co/x402fix/v1/lite' \
  -H 'content-type: application/json' \
  --data-raw '{"url":"https://api.youraitools.co/counterpartycheck/v1/lite"}'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://api.youraitools.co/x402fix/v1/lite' \
  -H 'content-type: application/json' \
  --data-raw '{"url":"https://api.youraitools.co/counterpartycheck/v1/lite"}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.005 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.005" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.005 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.youraitools.co%2Fx402fix%2Fv1%2Flite&method=POST
const res = await pay("https://api.youraitools.co/x402fix/v1/lite", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "url": "https://api.youraitools.co/counterpartycheck/v1/lite"
  }),
});
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.005 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.005"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://api.youraitools.co/x402fix/v1/lite",
        json={
            "url": "https://api.youraitools.co/counterpartycheck/v1/lite",
        },
    )
    print(res.status_code, res.text)