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.