Connect e-Gov Law Search to Codex
Query e-Gov Law Search directly from Codex. Arlet links the two through one MCP connection and takes care of API keys.
This server connects your AI client to the e-Gov Laws API (Version 2), the official database of Japanese legislation operated by the Digital Agency. It covers the Constitution, acts, cabinet orders, imperial orders, ministerial ordinances, and rules.
Key features:
- Find laws by title (partial match) or by law number, optionally filtered by law type.
- Run a full-text keyword search across the body text of all current laws and get matching sentence snippets.
- Fetch the text of a law as readable plain text. Long laws are truncated, so you can point at a specific article (e.g. MainProvision-Article_90) or request the text as it stood on a past date (asof).
- List a law's amendment history: amending laws, promulgation and enforcement dates, and future scheduled amendments.
The e-Gov Laws API is a public API provided free of charge by the Japanese government, so no API key or account is required. Results always reflect the official consolidated text published on e-Gov.
How to connect e-Gov Law Search to Codex
- 1
In the Arlet dashboard, open Data tools, find e-Gov Law Search and switch it on. No API key setup is needed.
- 2
In your terminal, run codex mcp add arlet --url https://mcp.arlet.dev/mcp/ to add Arlet as an MCP server.
- 3
Codex detects OAuth support and opens your browser. Sign in with Google and click Allow on the consent screen.
- 4
Once connected, both the CLI and the IDE extension can call Arlet tools (the configuration is shared).
If the browser does not open, run codex mcp login arlet to redo the authentication.