Jp Crypto Tax Rules

io.github.kodandyPublished by GitHub account kodandyv0.1.0Updated Oct 24, 2026

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

VerifiedStreamable HTTPWeb executableFinanceKnowledge & Memory

Overview

AI-generated overview

Remote MCP server giving assistants structured, cited Japanese crypto-asset tax rules, parameters and scenario rule packs.

What you can do
  • Browse and filter the catalog of Japanese crypto-asset tax rules by category, taxpayer and tax year
  • Read a single rule in full, including statement, exceptions, status, effective dates and statutory citations
  • Retrieve tax parameters such as income brackets, resident tax and surtax figures, the 2028 reform rate and filing thresholds
  • Fetch a scenario-curated rule pack for DeFi staking, overseas exchanges, corporate holding or the 2028 transition
When to use it
Useful when an assistant needs to answer questions about Japanese crypto-asset taxation and should ground answers in structured rules with statutory citations, including the current regime versus the pending 2028 reform.
Requirements
A remote Streamable HTTP endpoint; no API key and no initialize handshake. The paid rule-pack tool requires an x402 payment in USDC on Base (testnet during the current private beta).
Before you install
The paid rule pack costs 0.05 USDC per call and settles a real x402 payment. The content is general tax-system information, not tax advice, and does not address individual circumstances; verify against primary sources. The server is in a closed private beta, so rules, scope and pricing may change.

Installation

In SourceWeft

  1. Open Jp Crypto Tax Rules in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.kodandy%2Fjp-crypto-tax-rules/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

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

README

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.

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.

ToolPricingReturns
list_tax_rulesFreeRule catalog, filterable by category / taxpayer / tax_year (resolves the applicable epoch)
get_tax_ruleFreeOne rule in full: statement, exceptions, statutory citations, sources
get_tax_parametersFreeTax-rate tables and thresholds with sources (income brackets, 20.315% breakdown, filing threshold)
get_rule_pack0.05 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

Source: README.md at commit 1b0e7bf

Tools

4

list_tax_rules

List structured Japanese crypto 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。

Parameterscategorytax_yeartaxpayer

get_tax_rule

Full structured rule record (rule_id lookup)

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。

Parametersrule_idrequired

get_tax_parameters

Japanese tax parameters (brackets, rates, thresholds)

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。

Parameterstax_year

get_rule_pack

Curated scenario rule pack (x402 metered)

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。

Parametersscenariorequired

Version history

1
  1. v0.1.0LatestSep 16, 2026

Score

100% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts