AI Inference · x402 · early usage

Japan crypto-asset tax: realized income under the NTA total-average or moving-average m…

Japan crypto-asset tax: realized income under the NTA total-average or moving-average method (sell/spend/exchange as disposals, fees deductible, opening balances). Verified against the official NTA FAQ examples to the yen. Max 300 transactions per call. $0.05…

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

30d calls3

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

{
  "transactions": [
    {
      "asset": "BTC",
      "qty": 4,
      "total_jpy": 4000000,
      "type": "buy"
    },
    {
      "asset": "BTC",
      "qty": 0.2,
      "total_jpy": 210000,
      "type": "sell"
    }
  ]
}

Output example

{
  "as_of": "2026-08-21",
  "assumptions": [
    "国税庁の「暗号資産の計算書」様式は単価の1円未満を切り上げる運用が知られており、割り切れない単価では本エンジンの厳密計算と数円の差が生じうる(様式再現モードは将来課題)"
  ],
  "billable": true,
  "breakdown": [],
  "carried_forward": [],
  "disclaimer": "仮定条件に基づく概算試算。税務相談・手続代行・法律相談ではない。申告・届出への使用不可。確定額は官公署または税理士・社会保険労務士等に確認のこと。",
  "not_covered": [
    "DeFi(流動性提供・レンディング)・NFT",
    "ハードフォーク・エアドロップの取得価額",
    "マイニング・ステーキング・レンディング報酬の取得時所得",
    "事業所得該当性の判定(収入300万円超+帳簿保存)",
    "信用取引・証拠金取引の建玉管理",
    "国外取引所の年間取引報告書がない場合の残高照合",
    "法人税(法定評価方法が異なる)"
  ],
  "note": "SAMPLE RESPONSE generated by the exact deterministic engine that serves production (jp-statutory has no LLM: same input always produces this byte-identical result, carrying the same rules_version and cited primary sources). Served free at /samples/{product} so you can verify the response shape, the rules_version field and the source citations before paying. No payment was taken. The sample_input shown is the catalog example input that produced this output.",
  "ok": true,
  "result": {
    "income_classification": "雑所得(その他雑所得)が原則(FAQ 2-2)",
    "loss_note": null,
    "method": "total_average",
    "per_asset": [
      {
        "asset": "BTC",
        "cost_of_sales_jpy": 200000,
        "fees_jpy": 0,
        "method": "total_average",
        "proceeds_jpy": 210000,
        "quantity_disposed": 0.2,
        "quantity_year_end": 3.8,
        "realized_income_jpy": 10000,
        "unit_price_year_end_jpy": 1000000,
        "year_end_valuation_jpy": 3800000
      }
    ],
    "total_realized_income_jpy": 10000
  },
  "rules_version": "2026.08.18",
  "sample": true,
  "sample_input": {
    "transactions": [
      {
        "asset": "BTC",
        "qty": 4,
        "total_jpy": 4000000,
        "type": "buy"
      },
      {
        "asset": "BTC",
        "qty": 0.2,
        "total_jpy": 210000,
        "type": "sell"
      }
    ]
  },
  "sources": [
    "https://www.nta.go.jp/publication/pamph/pdf/0023012-176.pdf"
  ],
  "summary": "1資産・総平均法: 年間実現損益 10,000円(雑所得)",
  "tool": "jp-crypto-tax",
  "unverified_rules": []
}

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/31255.json for the price and payment options.
Pay. Call GET https://mart402.com/v1/jp-crypto-tax. 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: $0.05 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base
Demand: 3 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	$0.05	0xE3244a21D0d68bFa78b7CAd8C3b8777aDFbB3188	120s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xE3244a21D0d68bFa78b7CAd8C3b8777aDFbB3188",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "50000",
    "amountUsd": 0.05,
    "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/jp-crypto-tax"
# -> 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/jp-crypto-tax");
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/jp-crypto-tax")
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/jp-crypto-tax
Machine-readable: /resources/31255.json