io.github.kodandy/jp-crypto-tax-rules

Official4 tools

by kodandy

Machine-readable Japanese crypto-asset tax rules for AI agents: rules-as-code with citations, x402.

Machine-readable Japanese crypto-asset tax rules and calculations for AI agents.

Captured live from the server via tools/list.

list_tax_rules

FREE — returns structured rules. Catalog of machine-readable Japanese crypto-asset tax rules (rules-as-code): titles, status (current / enacted_pending), effective dates and statutory citations, filterable by category, taxpayer and tax_year. tax_year resolves the current-vs-2028-reform epoch per rule (applies / pending_enforcement). Sources are public only (NTA FAQ, e-Gov statutes, MOF documents); not tax advice. 一般的な税制情報の提供であり、個別の税務判断は税理士にご相談ください。

Parameters (3)

categorystring
Category filter: corporate | cost_basis | filing | income_classification | reform_2028 | taxable_events
taxpayerstring
Taxpayer filter: all | corporate | individual
tax_yearinteger
Tax year to resolve rule applicability, e.g. 2026 or 2028

get_tax_rule

FREE — returns one full structured rule: statement, exceptions, status, effective dates, machine tags and statutory citations (sources), served verbatim from the versioned rules corpus. Not tax advice. 一般的な税制情報の提供であり、個別の税務判断は税理士にご相談ください。

Parameters (1)

rule_idstringrequired
Rule id, e.g. jp.crypto.income.classification.individual

get_tax_parameters

FREE — returns structured tax parameters with per-value sources: progressive income tax brackets, resident tax and reconstruction surtax figures, the 2028-reform separate-taxation rate and loss-carryforward years, and the salary-filer filing threshold. Approximate reference values from public sources; not tax advice. 一般的な税制情報の提供であり、個別の税務判断は税理士にご相談ください。

Parameters (1)

tax_yearinteger
Tax year for epoch annotation of pending-reform rules, e.g. 2026 or 2028

get_rule_pack

Scenario-curated bundle of full structured rules (statements, citations, parameters) for one use case: defi_staking | overseas_exchange | corporate_holding | transition_2028. Paid via x402: each call costs 0.05 USDC. This tool returns the HTTP 402 payment challenge (spec-conformant accepts list) for the pack resource. The 402 is real: settle it against /v1/packs/{scenario} with an X-PAYMENT header and the 200 response delivers the full pack body ({status:"settled", settlement, pack}) — payment buys the actual structured rules, not a receipt. Not tax advice. 一般的な税制情報の提供であり、個別の税務判断は税理士にご相談ください。

Parameters (1)

scenariostringrequired
Scenario pack to retrieve: defi_staking | overseas_exchange | corporate_holding | transition_2028

README.md3 KBView on GitHub

JP Crypto Tax Rules — MCP Server

Remote MCP server exposing machine-readable rules-as-code for Japanese crypto-asset taxation to AI agents — structured rules with statutory citations, tax parameters, and the current-vs-2028-reform transition logic. Built from public sources only.

MCP endpoint (Streamable HTTP, stateless): https://jp-crypto-tax-rules-62ko7b2uwa-an.a.run.app/mcp
Machine index: llms.txt · API contract: openapi.yaml
Sibling gateways: jp-m2m-mcp (corporate records) · jp-biz-opportunity-mcp (tenders & subsidies)

Not tax advice. This is general tax-system information served as structured rules with citations. It does not respond to individual circumstances and is not a substitute for advice from a licensed tax professional (税理士). Always verify against primary sources.

Tool	Pricing	Returns
`list_tax_rules`	Free	Rule catalog, filterable by category / taxpayer / tax_year (resolves the applicable epoch)
`get_tax_rule`	Free	One rule in full: statement, exceptions, statutory citations, sources
`get_tax_parameters`	Free	Tax-rate tables and thresholds with sources (income brackets, 20.315% breakdown, filing threshold)
`get_rule_pack`	0.05 USDC (x402)	Scenario-curated bundle: `defi_staking`, `overseas_exchange`, `corporate_holding`, `transition_2028`

The paid tool genuinely fulfills: a settled x402 payment returns the rule pack itself, not a placeholder.

Connect

bash

claude mcp add --transport http jp-crypto-tax https://jp-crypto-tax-rules-62ko7b2uwa-an.a.run.app/mcp

json

{
  "mcpServers": {
    "jp-crypto-tax": {
      "type": "streamable-http",
      "url": "https://jp-crypto-tax-rules-62ko7b2uwa-an.a.run.app/mcp"
    }
  }
}

No API key and no initialize handshake required. USDC on Base (testnet during the current private beta).

Scope & sources

Epochs: current regime (miscellaneous income, total-average / moving-average cost basis, through FY2027 returns) and the FY2026 reform (20.315% separate taxation, 3-year loss carryforward) marked enacted_pending until the enforcement date is fixed.
Sources: 国税庁暗号資産FAQ (令和7年12月版), the relevant 所得税法 / 法人税法 / 消費税法 provisions via e-Gov, and the 令和8年度税制改正大綱. Every rule carries its own citations.
Status: closed private beta. Rules, scope and pricing may change. Source of the gateway lives in a private repository; this repo hosts the public MCP documentation and registry manifest.

License

MIT

Install

claude_desktop_config.json

{
  "mcpServers": {
    "jp-crypto-tax-rules": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://jp-crypto-tax-rules-62ko7b2uwa-an.a.run.app/mcp"
      ]
    }
  }
}

Desktop config is stdio-only; this bridges via mcp-remote. Native remote: Settings > Connectors.