Jp Eli Mcp

io.github.matematicsolutionsPublished by GitHub account matematicsolutionsv0.3.3Updated Oct 24, 2026

MCP server for Japan's e-Gov law search API: search, fetch, and cite national legislation.

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Overview

AI-generated overview

Read-only MCP server for Japan's official e-Gov law API, letting an assistant search, fetch and cite Japanese national legislation.

What you can do
  • Search laws by partial title or full-text keyword, with highlighted snippets
  • Fetch metadata for a law: title, law number, promulgation date
  • Retrieve a single article by law ID and article number, or the full text of a law (truncated for very large laws)
  • Report coverage: which law families are included, when they were captured, and what is not covered
  • Attach a citation contract to every response: a durable e-Gov viewer link, a human-readable citation and a source URL
When to use it
Useful when an assistant needs to look up Japanese statutes, cabinet orders or ministerial ordinances and quote them with verifiable citations, for example in legal research, compliance checks or drafting that depends on current Japanese law.
Requirements
Runs locally as a Python package (jp-eli-mcp), normally via uvx or python -m jp_eli_mcp; the README notes it may need installing from source until a release ships. No API key is needed. Optional environment variables set the API base URL, cache directory and audit directory. Network access to the e-Gov law API is required.
Before you install
Read-only against public e-Gov data, but every tool call is appended to a local audit log file. Optional environment variables can redirect the API base URL and change where cache and audit files are written. Full text of very large laws is truncated, so long statutes may be incomplete; verify citations against the returned source URL.

Installation

In SourceWeft

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

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

jp-eli-mcp

An MCP server for Japan's official e-Gov law search API (laws.e-gov.go.jp), run by the Digital Agency. It searches, fetches, and cites national legislation - acts, cabinet orders, ministerial ordinances - with a verifiable citation on every response.

Part of the MateMatic eu-legal-mcp production line, extended into Asia. Same citation contract (a stable identifier + a human-readable citation + a source URL) as the 18 EU/EEA connectors, adapted for a jurisdiction with no ELI scheme.

Scope. Discovery is by law title (jp_search_laws) or full-text keyword (jp_search_by_keyword); fetch a specific article (jp_get_article) or the full text (jp_get_full_text, truncated for very large laws such as the Civil Code). Every response carries a dataset_note.

Licence. e-Gov law data is official public information published by the Japanese government as open data (keyless, REST/JSON). This connector relays it with attribution and a source_url.

The tools

ToolWhat it does
jp_search_lawsSearch laws by (partial) title.
jp_search_by_keywordFull-text search across all laws, with highlighted snippets.
jp_get_lawMetadata for a law by law_id: title, law number, promulgation date.
jp_get_articleThe text of one article of a law, by law_id and article_num.
jp_get_full_textThe full text of a law (truncated at ~300,000 characters).
jp_coverageDeclare what this connector covers, when each family was captured, and - explicitly - what it does NOT cover. Every gap carries a fallback.

Every response carries the contract: eli_uri (Japan has no ELI - this is the durable e-Gov viewer URL, e.g. https://laws.e-gov.go.jp/law/129AC0000000089, see eli_note), human_readable_citation (e.g. 民法（明治二十九年法律第八十九号）), and source_url (the machine-readable API URL).

Install

Not yet on PyPI - install from source until the first release ships:

bash
git clone https://github.com/matematicsolutions/jp-eli-mcpcd jp-eli-mcppip install -e .

Once released, this will be uvx jp-eli-mcp.

Configuration via env:

  • JP_ELI_BASE_URL - default https://laws.e-gov.go.jp/api/2
  • JP_ELI_CACHE_DIR - default ~/.matematic/cache/jp-eli
  • JP_ELI_AUDIT_DIR - default ~/.matematic/audit

No API key. e-Gov's law search API is keyless.

Configure (Claude Code / any MCP client)

json
{  "mcpServers": {    "jp-eli-mcp": { "command": "jp-eli-mcp" }  }}

Windows 11 with Smart App Control

Smart App Control blocks unsigned executables, which covers uvx.exe, pip.exe and the jp-eli-mcp.exe launcher that pip writes at install time. The python.exe and py.exe from the python.org installer are signed by the Python Software Foundation, so running the module through the interpreter works:

bash
python -m pip install jp-eli-mcppython -m jp_eli_mcp

pip.exe is blocked for the same reason, so install with python -m pip, not pip install. If python is not on PATH, use the Windows launcher: py -3 -m jp_eli_mcp.

json
{ "mcpServers": { "jp-eli-mcp": { "command": "python", "args": ["-m", "jp_eli_mcp"] } } }

Do not turn Smart App Control off to work around this - it cannot be re-enabled without reinstalling Windows.

Governance

  • Public data only - read-only against e-Gov; no client data leaves the machine.
  • Audit log - every tool call appends one JSON line to ~/.matematic/audit/jp-eli-mcp.jsonl.
  • Vendor-neutral - talks only to laws.e-gov.go.jp; no LLM provider, no telemetry.
  • Verifiable citations - every response is independently checkable via source_url.

See CONSTITUTION.md and DISCOVERY.md.

Tests

bash
pip install -e ".[dev]"pytest tests/test_instructions_drift.py -v   # offlinepytest tests/test_smoke.py -v                # hits live e-Gov

Licence

Apache-2.0. © Matematic Solutions / Wieslaw Mazur.

Source: README.md at commit d5769b2

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

1
  1. v0.3.3LatestSep 16, 2026

Score

50% 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 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts