Japan Law Search

Official3 toolsLive

by fujimura-ui · TypeScript

Full-text search of all current Japanese laws (official e-Gov data), down to exact article text.

Captured live from the server via tools/list.

search_laws

日本の現行法令（法律・政令・省令など約1万件）を政府公式データベース（e-Gov）から検索する。search_in=full_text（既定）は条文本文の全文検索、search_in=titleは法令名検索。結果のlaw_idをget_law_structure / get_law_articleに渡すと条文を参照できる。

Parameters3

query	string	required	検索語（例: 電子署名 / 個人情報 / 解雇）
search_in	string	optional	full_text=条文本文を全文検索（既定） / title=法令名で検索
limit	integer	optional	最大件数（1〜20）

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "type": "string",
      "minLength": 1,
      "description": "検索語（例: 電子署名 / 個人情報 / 解雇）"
    },
    "search_in": {
      "default": "full_text",
      "description": "full_text=条文本文を全文検索（既定） / title=法令名で検索",
      "type": "string",
      "enum": [
        "full_text",
        "title"
      ]
    },
    "limit": {
      "default": 5,
      "description": "最大件数（1〜20）",
      "type": "integer",
      "minimum": 1,
      "maximum": 20
    }
  },
  "required": [
    "query"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

get_law_structure

law_idを指定して法令の構造（章・節・条の見出し一覧）を取得する。どの条文を読むべきか当たりを付けるのに使う。law_idはsearch_lawsの結果に含まれる。

Parameters1

law_id

string

required

法令ID（例: 412AC0000000102）

Raw schema

{
  "type": "object",
  "properties": {
    "law_id": {
      "type": "string",
      "minLength": 1,
      "description": "法令ID（例: 412AC0000000102）"
    }
  },
  "required": [
    "law_id"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

get_law_article

law_idと条番号を指定して条文の本文を取得する。条番号は「3」「第3条」「第三条の二」「3の2」のいずれの形式でもよい。

Parameters2

law_id	string	required	法令ID（例: 412AC0000000102）
article	string	required	条番号（例: 3 / 第3条 / 第三条の二）

Raw schema

{
  "type": "object",
  "properties": {
    "law_id": {
      "type": "string",
      "minLength": 1,
      "description": "法令ID（例: 412AC0000000102）"
    },
    "article": {
      "type": "string",
      "minLength": 1,
      "description": "条番号（例: 3 / 第3条 / 第三条の二）"
    }
  },
  "required": [
    "law_id",
    "article"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

README.md3 KBView on GitHub

Japan Law Search MCP — 日本の法令検索

Give your AI agent authoritative access to all ~10,000 Japanese laws and regulations.

This MCP server searches and retrieves the full text of current Japanese legislation — acts, cabinet orders, and ministerial ordinances — from the official e-Gov Laws API (Government of Japan). Built for legal-tech, compliance, HR, and contract-review AI agents working with Japanese law.

Why this server?

Japanese statutes are published as deeply nested XML with kanji numerals, era-based dates, and no convenient full-text API surface for LLMs. This server turns that into three clean, token-efficient tools.

Tools

`search_laws`

Full-text search across the body text of every current law (or search by law title). Returns matched snippets, law categories, promulgation dates, and official links.

`get_law_structure`

Table of contents for any law: chapters, sections, and article headings. Long statutes (e.g. the Civil Code with 1,000+ articles) are automatically compressed to chapter level to save tokens.

`get_law_article`

Retrieve the exact text of any article. Accepts flexible references — 3, 第3条, 第三条の二, 3の2 — and normalizes kanji numerals automatically. Output preserves paragraph and item numbering as clean plain text.

Example queries your agent can now answer

「電子署名法で電子署名が有効とされる条件は？」→ finds Article 3 and quotes it verbatim
"What does the Labor Standards Act say about overtime limits? Quote the exact article."
「個人情報保護法の目次を見せて、第三者提供に関する条文を特定して」

Data source & freshness

Official e-Gov Laws API v2 (Government of Japan), fetched live on every call — always the currently enforced revision, including amendments enforced this month.

Pricing

Pay per tool call. One search, one table of contents, or one article retrieval = one event. No subscription, no minimum.

日本語

日本の現行法令（約1万件）を全文検索し、条文を取得できるMCPサーバーです。巨大な法令XMLをAIが読みやすいテキストに整形し、「第三条の二」等の表記ゆらぎも自動吸収します。リーガルテック・コンプライアンス・労務系AIに最適です。

Get started

This is a hosted (remote) MCP server, available on Apify Store:

👉 https://apify.com/e-asakura/japan-law-search-mcp

The store page includes setup instructions for Claude, ChatGPT, Cursor, and any MCP-compatible client. Pay-as-you-go: $0.02 per tool call, no subscription.

Built by Edward Asakura — Japanese data infrastructure for AI agents. Part of the SEKISHO series: subsidies / laws / parliament.

Install

Tools (3)

search_lawsget_law_structureget_law_article

Remote endpoint

Streamable HTTP

Hosted server - connect over the network, no local install.

url

https://horei-mcp.plus-synergy.workers.dev/mcp

Add to VS Code Add to Cursor

claude_desktop_config.json

json

{
  "mcpServers": {
    "japan-law-search-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://horei-mcp.plus-synergy.workers.dev/mcp"
      ]
    }
  }
}

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