Licensing and attribution
JMAD joins facts from sources that carry different licences. This page lists them and what that means for you as a consumer of the joined data.
Licence per source
| Source | Licence | Typical fields |
|---|---|---|
| OpenStreetMap | ODbL | Names, footprint, height, floor counts, venue tags |
| Nominatim | ODbL (derived from OSM) | Address, postcode, prefecture code |
| Wikidata | CC0 | Names, year built, height, floor counts, architect |
| PLATEAU | CC BY 4.0 | Footprint, height, floor counts, asset type, name, address (ward/machi-aza granularity only). A yearBuilt field is declared but has not been observed populated in the Tokyo sample data the loader was built against |
| e-Stat | CC BY 4.0 | Prefecture/ward/machi-aza area codes, names, and census boundary polygons |
| Address Base Registry | Dataset-specific terms; catalogued samples mark CC BY 4.0 | Prefecture/ward/machi-aza area codes and representative points |
| EDINET | Government open data, PDL 1.0 | Matched ownership, physical and financial disclosures |
J-REIT issuer portfolios (jreit) | Publisher-specific terms, registered as proprietary | Matched current holding facts, physical attributes and financial figures |
Tokyo green-building archive (greenarchive) | Proprietary (publisher asserts all rights reserved) | Name, address, 建築主, 延べ面積, floors, structure, completion, tenure |
Tokyo green-building label (greenbuilding) | Government open data | Name, address, 建築主, 延べ面積, tenure, completion |
管理計画認定 register (mankan) | Government open data | Name, address, completion, unit count, structure, floors, certification date |
MLIT 不動産情報ライブラリ (reinfolib) | Government open data | Area-level transaction prices only; not on buildings |
JMAD (dnk) | Derived | Computed fields such as gfaM2 and centroid |
J-REIT portfolio ingestion and selected EDINET filing ingestion are implemented. EDINET requires an API key and selected report IDs. The Tokyo green-building sources are implemented; mankan loads from a periodically captured snapshot. Foursquare and the 登記 (touki) registry are not implemented. Implemented loaders do not establish nationwide coverage.
What to carry
ODbL (OpenStreetMap, Nominatim) and CC BY 4.0 (PLATEAU, e-Stat) both require attribution when you redistribute data drawn from them; ODbL also expects a derivative database you share back out to stay open under the same terms. Nominatim's own usage policy additionally asks for the attribution string "Data © OpenStreetMap contributors, ODbL 1.0" wherever its reverse-geocoded fields (addressJa, postcode, prefectureCode) are shown, since it derives entirely from OSM data. PLATEAU's own site policy likewise asks for a stated source wherever its fields (footprintM2, heightM, floorsAbove, floorsBelow, assetTypes, nameJa, addressJa) are shown, with the attribution wording "出典：国土交通省 PLATEAUウェブサイト（当該ページのURL）" (source: MLIT PLATEAU website, URL of the page).
Wikidata uses CC0. "Government open data" is not a blanket exemption from attribution: follow each dataset's stated terms. The ABR terms require source attribution and identification of processing; they apply PDL1.0 unless another rule is marked. The catalogued Tokyo block and residence samples are marked CC BY 4.0. Parcel layers additionally carry registry-map terms. Preserve the source URL and dataset-specific licence alongside any normalized or derived ABR values. EDINET's terms require attribution and a processing notice for transformed content. JMAD retrieves filings through the official API and retains the document URL on each extracted field.
J-REIT issuer websites have publisher-specific terms. JMAD's free tier is a product access designation, not a blanket licence for the underlying documents. Preserve the issuer and document URL; do not treat the extracted facts as permission to republish page text or images. The same distinction applies to other proprietary sources.
Computed fields are marked derived. Computation does not automatically remove obligations attached to the source datasets. Practically, if you're citing a specific field rather than redistributing a whole dataset, the safest habit is to keep the field's own source and URL attached wherever you use it.
How attribution travels with the data
Every field's provenance names its source. In the JSON API, that's the provenance.source and provenance.sourceUrl on the field. In a page's Markdown twin, the same information appears in a Sources section listing each contributing source, the record it pulled from, and the URL it came from. Neither format asks you to go dig up a licence separately: the source name on the field is enough to look up which table above applies.
The public layer stays open
Public, unauthenticated access to JMAD (no key, no signup) covers the free tier of fields, which is most of them: names, address, footprint, floor counts, height, year built. That doesn't change when the enriched and proprietary tiers ship. See authentication for what "no key" actually means today, and the field dictionary for which fields sit at which tier.
See provenance and precedence for the full shape of a field's provenance record.
Software notices
The polygon calculations use polygon-clipping and its dependencies. Their package licences and available licence texts are included in JMAD's third-party notices. These software notices are separate from the source-data licences above.
Updated 1 day ago