ekidata

ekidata is a small local bridge to a hosted MCP server that relays official Japanese public data in English: municipality and station context, accessible-toilet lookups, station hazard categories from MLIT data, station search, live JMA river and landslide alerts, and Tokyo-area train status.

The bridge keeps no dataset of its own. It serves the upstream server's tool list locally, exactly as captured from the live endpoint, and forwards each tool call upstream, returning the result untouched. Every tool in the captured surface only reads public data.

Tools

• ping — connection test and freshness check. No arguments and no required fields.

• get_municipality_context — official data for a municipality by 5-digit code or exact name. Required: name_or_code. Optional: fields.

• get_station_context — the same municipality context resolved from a station name or station_id. Its captured schema carries an empty required list, so either identifier may be supplied.

• get_toilet_by_station — accessible toilets inside a station, with floor, equipment and nearest exit. Required: station.

• get_public_toilet_by_city — public toilets in a municipality, with accessibility flags, address and coordinates. Required: city.

• get_station_hazard — official disaster-risk categories at a station, relayed from MLIT data. Required: station_name.

• station_search — find stations by describing what should be around them, in English or Japanese, with optional filters such as name_contains, pref, limit, ramen, toilet, diaper and flood-rank options. Required: q.

• get_active_alerts — live JMA river flood forecasts and landslide alerts. Optional: area. No required fields.

• get_station_alerts — those same JMA alerts for a station's prefecture. Required: station_name.

• get_train_status — live Tokyo-area train service status by line or station name. Required: query.

Related MCP server: japan-transit-mcp

Configuration

• GACHI_MCP_URL (optional) — override the upstream endpoint. Defaults to https://api.gachi-tokusuru.com/mcp. (The override hook is this rebuild's own labelled reconstruction.)

• GACHI_API_KEY (optional) — when set, every upstream request carries an Authorization: Bearer <key> header. When it is not set, no auth header is sent. (This forwarding is also a labelled reconstruction; the original surface was captured keyless.)

Forwarding mechanics

On the first tool call the client opens a streamable HTTP session with the upstream: a JSON-RPC initialize request (protocolVersion 2025-03-26, clientInfo name ekidata), then a notifications/initialized notification, then the tools/call request carrying the caller's arguments unchanged. When the upstream answers initialize with an Mcp-Session-Id header, that value rides on every later request of the session, which is reused for the life of the process. Replies may arrive as plain JSON or as server-sent events; both are read.

Successful upstream results pass through verbatim, including any isError flag the upstream sets. Failures — a JSON-RPC error, a non-2xx status, an unreadable response, or a request that cannot be completed — come back as an isError result whose text starts with ekidata error: (this rendering is this rebuild's own labelled reconstruction).

CLI

Each tool is also a subcommand taking one JSON argument string (omit it for tools that take none):

npx @reneturcios/ekidata ping
npx @reneturcios/ekidata get_municipality_context '{"name_or_code":"13104"}'
npx @reneturcios/ekidata station_search '{"q":"terminal station with late-night ramen"}'
npx @reneturcios/ekidata get_train_status '{"query":"Yamanote"}'
npx @reneturcios/ekidata --version

Exit codes: 0 on success, 1 on an isError result, 2 on a usage error.

MCP server

npx -y @reneturcios/ekidata mcp

MCP client config:

{
  "mcpServers": {
    "ekidata": {
      "command": "npx",
      "args": ["-y", "@reneturcios/ekidata", "mcp"]
    }
  }
}

Docker

docker run -i ghcr.io/cloudcorprecords/ekidata
docker run --rm ghcr.io/cloudcorprecords/ekidata --version

The container's default command is mcp, so the first form is a stdio MCP server; any other arguments reach the CLI normally.

Development

npm install
npm run build
npm test
npm run dev

The test suite runs entirely against a stubbed JSON-RPC upstream — no live network calls.

License

MIT — see LICENSE.