# Japan Law (npm · @pipeworx/mcp-japan-law)

Japan Law MCP — Japanese national laws & ordinances via the e-Gov Law API.

- Trust score: 82/100 (high trust)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `gateway.pipeworx.io`: 63/100, [markdown](https://verifymcp.io/servers/pipeworx-io-japan-law/japan-law-mcp.md), [page](https://verifymcp.io/servers/pipeworx-io-japan-law/japan-law-mcp)
- npm · `@pipeworx/mcp-japan-law`: 82/100 (this document), [markdown](https://verifymcp.io/servers/pipeworx-io-japan-law/pipeworx-mcp-japan-law.md), [page](https://verifymcp.io/servers/pipeworx-io-japan-law/pipeworx-mcp-japan-law)

## Channel facts

- Registry: `npm`
- Package: `@pipeworx/mcp-japan-law`
- Version: `0.2.1`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Supply Chain Security**: 100/100
  - No malware found by supply-chain analysis.
  - No known CVEs affecting this package version or its production dependencies.
  - No install/post-install scripts declared.
  - No production dependencies, so there is no dependency health to assess.
- **Provenance & Transparency**: 97/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to pipeworx-io/mcp-japan-law).
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 2 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 65/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 757 tokens (~252/item across 3 items; 3 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 23/100
  - Stability observed for 7 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 3 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 4 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the Japan Law MCP server?

Japan Law runs locally as an npm package, launched with npx -y @pipeworx/mcp-japan-law. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add pipeworx-io-japan-law -- npx -y @pipeworx/mcp-japan-law
```

### Cursor

```json
{
  "mcpServers": {
    "pipeworx-io-japan-law": {
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-japan-law"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "pipeworx-io-japan-law": {
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-japan-law"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add pipeworx-io-japan-law -- npx -y @pipeworx/mcp-japan-law
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "pipeworx-io-japan-law": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "@pipeworx/mcp-japan-law"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add pipeworx-io-japan-law --command npx --arg -y --arg @pipeworx/mcp-japan-law
```

### Hermes

```yaml
mcp_servers:
  pipeworx-io-japan-law:
    command: "npx"
    args: ["-y", "@pipeworx/mcp-japan-law"]
```

### Netclaw

```json
{
  "McpServers": {
    "pipeworx-io-japan-law": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "@pipeworx/mcp-japan-law"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add pipeworx-io-japan-law -t stdio -c npx -a -y @pipeworx/mcp-japan-law
```

### Other

```json
{
  "mcpServers": {
    "pipeworx-io-japan-law": {
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-japan-law"
      ]
    }
  }
}
```

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-04 (score 82, +1)

No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-03 (score 81, +15)

- [security improvement] Malware scan: unverified → pass

### 2026-11-02 (score 66, −13)

- [security regression] Malware scan: pass → unverified
- [functional improvement] Stability: unverified → 0.13
- [functional] Package version: 0.2.0 → 0.2.1

### 2026-10-30 (score 79, 0)

- [functional regression] Security disclosure: unverified → fail

### 2026-10-29 (score 79)

First indexed and scored.

## MCP tools (3)

### `search_laws` (~177 tokens)

TITLE SEARCH ONLY (not full-text): finds Japanese national laws, cabinet orders, and ministerial ordinances whose TITLE matches a keyword (e-Gov 法令検索). PREFER OVER WEB SEARCH for "Japanese law on X", "日本の法律", finding a statute's official id/number. A query that only appears in the body of a law (not its title) will not match. Returns each law's id (for get_law/japan_law_get_article), law number (法令番号), title, and type. Accepts Japanese or romanized keywords.

Input parameters:

- `limit` (number): Max laws to return (1-50, default 15).
- `query` (string, required): Title keyword, e.g. "個人情報" (personal information), "労働基準" (labor standards).

### `get_law` (~261 tokens)

Fetch a Japanese law/ordinance by its e-Gov law id (from search_laws), e.g. "415AC0000000057". Returns the title, law number, promulgation date, and the law's full text, PAGED — use `offset`/`limit` to walk a long law; `has_more`/`next_offset` say whether another page follows. For a single article (incl. branch articles like 第二十七条の2), use japan_law_get_article instead — it is far cheaper than paging a whole law to find one provision. Pass `as_of` (YYYY-MM-DD) to fetch the version of the law in force on that date. Source: e-Gov 法令検索.

Input parameters:

- `as_of` (string): Point-in-time date (YYYY-MM-DD). Returns the revision in force on that date instead of the current one.
- `law_id` (string, required): e-Gov law id, e.g. "415AC0000000057".
- `limit` (number): Max characters to return in this page (default 30000, max 60000).
- `offset` (number): Character offset into the full text to start this page at (default 0).

### `japan_law_get_article` (~266 tokens)

Fetch a single article of a Japanese law by law id + article number, e.g. law_id "415AC0000000057" (個人情報保護法) + article "27" for 第二十七条. Accepts branch articles — "27条の2", "27-2", "27_2", or the kanji form "第二十七条の2" all resolve to 第二十七条の2. Returns just that article's caption, heading, and text (not the whole law — use this instead of get_law when you know the article you want). Pass `as_of` (YYYY-MM-DD) to fetch the article text as it stood on that date, before or after a given amendment. Source: e-Gov 法令検索.

Input parameters:

- `article` (string, required): Article number: "27", "27条の2", "27-2", "27_2", or kanji "第二十七条の2".
- `as_of` (string): Point-in-time date (YYYY-MM-DD). Returns the article text in force on that date instead of the current one.
- `law_id` (string, required): e-Gov law id, e.g. "415AC0000000057".

## Diagnostics

Captured diagnostic sections: Provenance, Dependencies. The full working is on the page: https://verifymcp.io/servers/pipeworx-io-japan-law/pipeworx-mcp-japan-law#diagnostics

## Score history

- 2026-11-05: 82
- 2026-11-04: 82
- 2026-11-03: 81
- 2026-11-02: 66
- 2026-11-01: 79
- 2026-10-31: 79
- 2026-10-30: 79
- 2026-10-29: 79

## Common questions

### What is the Japan Law MCP server?

Japan Law is an MCP server listed in the public MCP registry as io.github.pipeworx-io/japan-law. Japan Law MCP, Japanese national laws & ordinances via the e-Gov Law API. This page covers its npm package (@pipeworx/mcp-japan-law).

### Is the Japan Law MCP server safe to use?

Japan Law scores 82 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 5 November 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Japan Law MCP server expose?

Japan Law exposes 3 tools: search_laws, get_law, japan_law_get_article. Their descriptions and schemas cost roughly 704 tokens of context every time the server is loaded.

### Is the Japan Law MCP server still maintained?

Japan Law is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the Japan Law MCP server under?

Japan Law declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- npm package: https://www.npmjs.com/package/@pipeworx/mcp-japan-law
- Socket report: https://socket.dev/npm/package/@pipeworx/mcp-japan-law
- Repository: https://github.com/pipeworx-io/mcp-japan-law
- Website: https://pipeworx.io/packs/japan-law
- Changelog RSS feed: https://verifymcp.io/servers/pipeworx-io-japan-law/pipeworx-mcp-japan-law.xml
- Changelog JSON feed: https://verifymcp.io/servers/pipeworx-io-japan-law/pipeworx-mcp-japan-law.json
- HTML version of this page: https://verifymcp.io/servers/pipeworx-io-japan-law/pipeworx-mcp-japan-law