Verify

{
  "accounting_json": {
    "currency": "JPY",
    "customer": null,
    "due_date": null,
    "invoice_no": null,
    "issue_date": null,
    "reg_no": "T1180301018771",
    "subtotal": 100000,
    "tax": 10000,
    "total": 110000,
    "vendor": "トヨタ自動車株式会社"
  },
  "checks": [
    {
      "check": "tax_rate_10pct",
      "detail": "net=100000 tax=10000 expected=10000",
      "pass": true
    },
    {
      "check": "invoice_reg_no_checkdigit",
      "detail": "reg=T1180301018771 cd=1 expected=1",
      "pass": true
    }
  ],
  "corp_registry": {
    "address_pref_city": "愛知県豊田市",
    "corporate_number": "1180301018771",
    "name": "トヨタ自動車株式会社",
    "note": "existence of the underlying corporate number in the Japan NTA corporate-number registry; NOT the qualified-invoice-issuer registration status. Sole proprietors are not in this registry, so not_found does not mean the number is invalid.",
    "source": "Japan NTA corporate number registry (houjin-bangou.nta.go.jp)",
    "status": "found",
    "vendor_name_match": "exact"
  },
  "note": "SAMPLE RESPONSE (recorded from a real production run). Served free at /samples/{product} so you can see the exact response shape before paying. No payment was taken.",
  "ok": true,
  "sample": true,
  "verified": true
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://mart402.com/v1/verify' \
  -H 'content-type: application/json' \
  --data-raw '{"fields":{"invoice_no":"SAMPLE-001","issue_date":"2026-09-05","tax_jpy":"100","total_jpy":"1100","vendor":"Sample Shoji K.K."}}'

# 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://mart402.com/v1/verify' \
  -H 'content-type: application/json' \
  --data-raw '{"fields":{"invoice_no":"SAMPLE-001","issue_date":"2026-09-05","tax_jpy":"100","total_jpy":"1100","vendor":"Sample Shoji K.K."}}' \
  | 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 $0.015 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.015" });
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 $0.015 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fmart402.com%2Fv1%2Fverify&method=POST
const res = await pay("https://mart402.com/v1/verify", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "fields": {
      "invoice_no": "SAMPLE-001",
      "issue_date": "2026-09-05",
      "tax_jpy": "100",
      "total_jpy": "1100",
      "vendor": "Sample Shoji K.K."
    }
  }),
});
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 $0.015 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.015"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://mart402.com/v1/verify",
        json={
            "fields": {
                "invoice_no": "SAMPLE-001",
                "issue_date": "2026-09-05",
                "tax_jpy": "100",
                "total_jpy": "1100",
                "vendor": "Sample Shoji K.K.",
            },
        },
    )
    print(res.status_code, res.text)