Arlet

Connect Corporate Number Publication Site (Houjin Bangou) to ChatGPT

Query Corporate Number Publication Site (Houjin Bangou) directly from ChatGPT. Arlet links the two through one MCP connection and takes care of API keys.

Enable Corporate Number Publication Site (Houjin Bangou) in ArletChatGPT connection guide (docs)

This server connects your AI client to the Corporate Number System Web API (Version 4) operated by Japan's National Tax Agency. Every registered corporation in Japan has a unique 13-digit corporate number, and this API is the authoritative source for the mapping between numbers, registered names, and head-office addresses.

Key features:

  • Search corporations by name (prefix or partial match), optionally narrowed by prefecture/municipality.
  • Resolve up to 10 corporate numbers at once to their registered name, address, corporation kind, and change/closure history.

Because the corporate number is the common key used by gBizINFO, EDINET, procurement data, and most other Japanese business datasets, this API is the natural first step for entity resolution: find the right corporate number first, then join everything else onto it.

Using the API requires a free application ID (γ‚’γƒ—γƒͺケーションID) issued by the NTA; apply on the Web API page of the Corporate Number Publication Site. Set it as HOUJIN_BANGOU_APP_ID in your Arlet environment variables.

How to connect Corporate Number Publication Site (Houjin Bangou) to ChatGPT

  1. 1

    In the Arlet dashboard, open Data tools, find Corporate Number Publication Site (Houjin Bangou), set the API key issued by Corporate Number Publication Site (Houjin Bangou) and switch it on.

  2. 2

    In ChatGPT, open Settings β†’ Plugins β†’ Browse plugins and click + at the top right.

  3. 3

    In the New Plugin form, enter "Arlet" as the Name, choose Server URL for Connection and enter https://mcp.arlet.dev/mcp/, pick OAuth for Authentication, check the risk acknowledgement and click Create.

  4. 4

    Open the Arlet plugin you created, click Sign in with Arlet, sign in with Google and click Allow. The connection is complete.

If the Plugins screen is not shown, turn on Developer mode under Settings β†’ Security and login.

Use Corporate Number Publication Site (Houjin Bangou) with other AI clients