Preflight Batch

{
  "checked_at": "2026-09-29T12:00:00.000Z",
  "count": 2,
  "counts": {
    "caution": 0,
    "go": 2,
    "no_go": 0,
    "unknown": 0
  },
  "results": [
    {
      "options": [],
      "reasons": [],
      "recommended_option": 0,
      "safe_to_pay": true,
      "summary": "OK to pay: $0.02 on Base.",
      "url": "https://ichimoku-signal.fizzl.eu/signal/BTC-USDT",
      "verdict": "go"
    },
    {
      "options": [],
      "reasons": [],
      "recommended_option": 0,
      "safe_to_pay": true,
      "summary": "OK to pay: $0.01 on Base.",
      "url": "https://presign-guard.fizzl.eu/v1/token",
      "verdict": "go"
    }
  ]
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://x402-doctor.fizzl.eu/api/v1/preflight/batch?max_usd=0.05'

# 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/preflight/batch?max_usd=0.05' \
  | 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%2Fx402-doctor.fizzl.eu%2Fapi%2Fv1%2Fpreflight%2Fbatch
const res = await pay("https://x402-doctor.fizzl.eu/api/v1/preflight/batch?max_usd=0.05");
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.get("https://x402-doctor.fizzl.eu/api/v1/preflight/batch?max_usd=0.05")
    print(res.status_code, res.text)