Fix

{
  "fixes": [
    {
      "checks": [
        "accepts[0]-amount"
      ],
      "code": [
        {
          "label": "Option field",
          "language": "json",
          "snippet": "\"amount\": \"10000\"",
          "stack": "generic"
        }
      ],
      "recipe": "amount",
      "severity": "warn",
      "steps": [
        "Use price: \"$0.01\" instead of an amount."
      ],
      "title": "Amount \"0.01\" → \"10000\" ($0.01)",
      "verify": "Run x402 Doctor again.",
      "why": "x402 amounts are integer strings in the smallest unit."
    }
  ],
  "overall": "fail",
  "stack": {
    "detected_from": "x-powered-by: Express",
    "id": "express",
    "name": "Express (@x402/express)"
  },
  "summary": "1 fix (0 blocking), for Express (@x402/express).",
  "unfixed": [],
  "url": "https://x402-doctor.fizzl.eu/demo/broken"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://x402-doctor.fizzl.eu/api/v1/fix?url=https%3A%2F%2Fx402-doctor.fizzl.eu%2Fdemo%2Fbroken'

# 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 - 'https://x402-doctor.fizzl.eu/api/v1/fix?url=https%3A%2F%2Fx402-doctor.fizzl.eu%2Fdemo%2Fbroken' \
  | 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 $0.05 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.05" });
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 $0.05 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fx402-doctor.fizzl.eu%2Fapi%2Fv1%2Ffix
const res = await pay("https://x402-doctor.fizzl.eu/api/v1/fix?url=https%3A%2F%2Fx402-doctor.fizzl.eu%2Fdemo%2Fbroken");
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 $0.05 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.05"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://x402-doctor.fizzl.eu/api/v1/fix?url=https%3A%2F%2Fx402-doctor.fizzl.eu%2Fdemo%2Fbroken")
    print(res.status_code, res.text)