# Gachi Data API — Japan Station & Accessibility Data (API · MCP · Open Datasets)

> Deep, obscure Japanese data you won't find anywhere else — stations, accessibility,
> vacancy, hazards. Hand-verified, English-first, built for AI agents.
> Free tier; MCP + REST share one key.

## API access
- MCP endpoint: https://api.gachi-tokusuru.com/mcp (JSON-RPC; tools: get_municipality_context, get_station_context, get_toilet_by_station, get_public_toilet_by_city, get_station_hazard, station_search, get_active_alerts, get_station_alerts, get_train_status)
- REST GET /v1/station-toilets/search?station=Shinjuku  (station name English or Japanese)
- REST GET /v1/toilets/nearby?lat=&lng=&radius=&wheelchair=&ostomate=&diaper=  (radius metres, max 2000)
- REST GET /v1/stations/{station_id}/hazard  (official MLIT hazard categories at a station, relayed live; station_id e.g. st_00001)
- REST GET /v1/municipalities/{code}/context · /v1/stations/{station_id}/context  (Municipality Context API: vacancy 2003-2023 × nearest-station ridership × hazard × land price × livability, one call per municipality or station; official values only, no scores; Free 1 municipality/day)
- Realtime Layer (live) — service status for 94 Tokyo-area train lines (delays, suspensions, resumptions) + nationwide JMA river flood forecasts & landslide warnings, station-matched. Alert coverage: nationwide. Station-matching: prefecture-level, nationwide (any station's pref) — or query by prefecture / JMA area code.
  - REST GET /v1/alerts/active · /v1/alerts/area/{code} · /v1/stations/{station_id}/alerts  (JMA river flood forecasts (levels 2-5) & landslide alerts ONLY — not general weather warnings, not earthquakes; each response has a coverage array; relay of official facts, not a warning we issue)
  - REST GET /v1/lines/status · /v1/lines/{line_id}/status · /v1/stations/{station_id}/lines/status  (ODPT train service status; enum normal/delayed/suspended/resumed)
  - Every realtime response carries fetched_at (+ source_published_at for trains); stale data is flagged stale:true or 503, never returned silently.
  - Provenance: facts observed from public web ramen listings; records cross-checked against Japanese municipality open data (© 各自治体オープンデータ, CC BY); municipality via reverse geocoding © 国土地理院 (GSI); freshness/keito/payment/romanization layers are original © gachi-tokusuru.com. Joins to the Japan Station Master via station.id (st_xxxx).
- Our JMA pipeline also powers a public alert feed on X (@gachi_tokusuru) — proof the relay is alive.
- Auth: Authorization: Bearer <key>. Free keys: https://api.gachi-tokusuru.com
- OpenAPI: https://api.gachi-tokusuru.com/openapi.yaml
- Example analyses (Data Stories): https://api.gachi-tokusuru.com/docs#data-stories
- Pricing: https://api.gachi-tokusuru.com (Free 1k, Pro $19/100k, All Access $49/200k, Business $149/500k)

## Free open datasets (citable, annually updated)
- Japan Station Master (entity-resolved, 9,145 stations nationwide) + Ridership 2000-2025 (station_id shared)
- Housing Vacancy 2003-2023 (1,653 municipalities, 5 national surveys, with merger crosswalk)
- Municipality Context API (live): vacancy × ridership × hazard × land price × livability, per municipality or station — official values only, no scores
- Zenodo DOI (concept, always latest): 10.5281/zenodo.21199500  (https://doi.org/10.5281/zenodo.21199500)
- GitHub: https://github.com/eng213035/gachi-open-datasets
- Kaggle: https://www.kaggle.com/datasets/gachidata/japan-stations-ridership-and-akiya-2003-2025

## License & attribution
- Accessible & public toilets: Tokyo Metropolitan Government (Bureau of Social Welfare) https://portal.data.metro.tokyo.lg.jp/ & BODIK municipal open data (CC BY 4.0) https://www.bodik.jp/
- Station names & train service status: ODPT (Public Transportation Open Data Center), CC BY 4.0 — https://developer.odpt.org/
- Hazard categories, future population, land price: MLIT 不動産情報ライブラリ (Real Estate Information Library), official values relayed as-is per request; not a government-created dataset — https://www.reinfolib.mlit.go.jp/
- River flood forecasts & landslide alerts: JMA (Japan Meteorological Agency, 気象庁), relayed as published, not warnings issued by this service — https://www.jma.go.jp/bosai/
- Housing vacancy & municipality codes: Statistics Bureau of Japan (住宅・土地統計調査) via e-Stat https://www.stat.go.jp/data/jyutaku/ , & MIC (総務省).
- Nationwide stations & bus stops: MLIT 国土数値情報 N02/P11 https://nlftp.mlit.go.jp/ksj/ ; English station names partly via Wikidata (CC0) https://www.wikidata.org/
- Derived by gachi-tokusuru.com (distinct from official values above): nearest_exit, nearest_station_km, and bus-stop counts are computed via spatial join. Accuracy/completeness not guaranteed.