Hourei

You can run the Hourei MCP Server to search and retrieve Japanese statute information via e-Gov APIs. It exposes clear tools to search laws, fetch full text data, and view amendment histories, enabling practical legal research, compliance checks, and reference in workflows and chatbots.

How to use

You use an MCP client to interact with the Hourei MCP Server. The server provides three core tools: search_law to find laws by name or number, get_law_data to fetch full text by law number, and get_law_revision to retrieve amendment histories. Configure your MCP client to point to the server using the provided command patterns, then invoke the tools with appropriate parameters to perform your tasks.

How to install

Prerequisites: make sure you have Node.js and npm installed on your system.

# Quick start using npx (recommended)
npx hourei-mcp-server

If you prefer to run locally from source, clone the project and install dependencies.

git clone <repository-url>
cd hourei-mcp-server
npm install

Configuration and usage notes

When you set up your MCP client, you can use the following stdio configurations to start the server via npx or via a local Node.js entry point.

{
  "mcpServers": {
    "hourei": {
      "command": "npx",
      "args": ["-y", "hourei-mcp-server"]
    }
  }
}

If you prefer to run the server from a local path for development or testing, you can start it with Node pointing directly to the entry script.

{
  "mcpServers": {
    "hourei_local": {
      "command": "node",
      "args": ["/path/to/hourei-mcp-server/index.js"]
    }
  }
}

Tools and usage overview

There are three tools you can call through the MCP server: search_law, get_law_data, and get_law_revision. Use search_law to look up laws by keyword and optional category filters, get_law_data to retrieve the full text by law number, and get_law_revision to view amendment histories.

Examples of common tasks

Search for laws related to a keyword, e.g., to find acts about privacy, labor standards, or consumption tax.

Fetch the full text of a specific law by its number, for example by providing the exact law number string.

Retrieve amendment histories to understand how a law has changed over time and to determine current applicability.

Available tools

search_law

Search for laws by keyword or law number with optional category filtering (law, ordinance, order, regulation, etc.) and limit the number of results.

get_law_data

Retrieve the full text of a law by its law number, returning structured data including article hierarchy.

get_law_revision

Obtain the amendment history for a given law number, including amendment details and effective dates.