MonstarX · Japan MCP

Japan's public data, ready for your AI.

Weather, earthquakes, geocoding, postal codes, holidays, evacuation shelters, tourism spots, Bank of Japan series, open datasets — Japan's free public APIs live across many agencies, each with its own formats and quirks. MonstarX unifies them into 27 tools any AI agent can call, through one endpoint, with no API keys. Stop writing integration glue. Start shipping Japan-smart products.

▶ Try it live in your browser Connect Claude or Cursor

ready-made tools

free public sources

API keys or signup

Live

real-time data

▶Live playground

Pick a tool, tweak the inputs, hit Run — the query goes straight to the live MCP server and streams back real Japan data. No sign-up, nothing to install. Try a one-click example to start:

Try

01What you can build

A weekend hackathon or a production feature — these are all a few tool calls away.

⛅

Weather-aware apps

Area codes, daily/weekly JMA text, 24h/4-day forecasts, UV, rain, and air quality for Tokyo or any prefecture office.

jp_weather_24hjp_weather_warningsjp_uv_index

🌋

Disaster awareness

Surface recent earthquakes, tsunami advisories, and nearby designated evacuation shelters.

jp_earthquake_listjp_tsunami_listjp_evacuation_shelters

📍

Maps & addressing

Search places, geocode, reverse-geocode, resolve postal codes, and read GSI elevation — all without keys.

jp_geocodejp_postal_codejp_elevation

🗾

Travel & tourism

Find nearby attractions from OpenStreetMap and pair with weather or holiday calendars.

jp_tourism_spotsjp_public_holidays

📈

Macro / finance bots

Pull Bank of Japan series such as overnight call rates into research or agent workflows.

jp_boj_finance

📚

Open data explorer

Search DATA.GO.JP / e-Gov packages, inspect metadata, and query datastore tables.

jp_datasets_searchjp_dataset_query

02Connect your agent

MonstarX Japan MCP is a remote HTTP server speaking the Model Context Protocol. Point any MCP-capable client at the endpoint — no auth handshake, it's stateless.

Claude Code

__CB_CC__

Cursor / native HTTP clients

__CB_CURSOR__

Claude Desktop — claude_desktop_config.json

__CB_DESK__

Or just cURL it

__CB_QS__

03Response format

Every call returns the payload twice — as a JSON string in content[0].text and as a parsed object in structuredContent (prefer this). Each payload wraps the data in a consistent provenance envelope so your agent always knows the source, agency and freshness.

__CB_ENV__

Field	Meaning
source	Upstream platform — JMA bosai, Open-Meteo, GSI, DATA.GO.JP, BOJ, zipcloud, etc.
agency	Originating body — Japan Meteorological Agency, GSI, Digital Agency, Bank of Japan, …
api	The specific upstream API that was queried.
license	Data licence / terms note when applicable.
retrieved_at	Server fetch time (UTC). Live timestamps inside payloads are often JST (+09:00).
data / results	The payload. List tools add context like `total`, `shown`, `found`.

04Errors

Errors come back as a normal result with isError: true and a message in content[0].text — not as a transport-level failure. Invalid or missing arguments return MCP error -32602. An empty list is a valid "no matches", not an error.

__CB_ERR__

05All 27 tools

Every tool is prefixed jp_; required params are marked *. Hit Try in playground on any tool to load it above with a working example.