Connect Corporate Number Publication Site (Houjin Bangou) to Claude
Query Corporate Number Publication Site (Houjin Bangou) directly from Claude. Arlet links the two through one MCP connection and takes care of API keys.
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’γγͺγ±γΌγ·γ§γ³ID) 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 Claude
- 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
In Claude, open Organization settings β Connectors from the account menu at the bottom left, then click + Add.
- 3
Choose Custom β Web, enter "Arlet" as the Name and https://mcp.arlet.dev/mcp/ as the Remote MCP server URL, then click Add. Authentication settings are auto-detected, so keep the defaults.
- 4
The first time you use it, sign in with Google. After that, every service you switched on in Arlet is available from Claude.
Adding a connector is done by an organization admin on Team / Enterprise plans. On Pro / Max you can add it for yourself from Settings β Connectors with the same steps.