Payments · x402 · early usage

Invoice field verification for AI agents: arithmetic consistency of invoice fields, lin…

Invoice field verification for AI agents: arithmetic consistency of invoice fields, line-item totals, JP registration number check-digit + corporate-number existence observation (official NTA registry), accounting JSON. 0.015/call.

by mart402.com · discovered, not yet claimed by its owner · updated 2026-10-08

30d calls5

30d payers2

MethodPOST

Outputjson

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

Tags: bazaar · offer-receipt

Call contract

Method: POST
Input: json
Output: json
Last paid call: 2026-10-08

Input example from Bazaar metadata

{
  "fields": {
    "invoice_no": "SAMPLE-001",
    "issue_date": "2026-09-05",
    "tax_jpy": "100",
    "total_jpy": "1100",
    "vendor": "Sample Shoji K.K."
  }
}

Output example

{
  "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
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/31261.json for the price and payment options.
Pay. Call GET https://mart402.com/v1/verify. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.015 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base
Demand: 5 calls · 2 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.015	0xE3244a21D0d68bFa78b7CAd8C3b8777aDFbB3188	120s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xE3244a21D0d68bFa78b7CAd8C3b8777aDFbB3188",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "15000",
    "amountUsd": 0.015,
    "maxTimeoutSeconds": 120
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "example": {
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

Example shape — generated from the schema, not a captured live response

{
  "example": {},
  "type": "string"
}

Examples

curl

curl "https://mart402.com/v1/verify"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://mart402.com/v1/verify");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
res = httpx.get("https://mart402.com/v1/verify")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: mart402.com
Endpoint: https://mart402.com/v1/verify
Machine-readable: /resources/31261.json