katastero-support

Privacy Policy – Katastero

Last updated: 2026-11-05

Katastero is a browser extension that displays official Spanish geographic data on real-estate portal maps and analyses parcels against public government geoservices.

Data collection

The extension collects no personal data. Nothing you view, click or analyse is sent to the developer or to any third-party analytics service. There is no telemetry, no tracking, no advertising, no account system.

The only third-party request is licence verification: when you activate a purchased licence key, the key and a random, per-install device id are sent directly to api.polar.sh (our store vendor / merchant of record) to register this device, and re-checked there about every three days. No browsing data, coordinates or listing data are included in these requests. Purchases themselves happen on Polar’s checkout; their own privacy policy applies there.

What the extension does with data

Map coordinates: When you click a map point or open a listing page, the clicked/listing coordinates are sent – directly from your browser – to the official public geoservices of the Spanish national administrations (Dirección General del Catastro, Ministerio de Vivienda, MITECO/IEPNB, IGN, IGME, INE, SIGPAC), the regional and foral authorities (Gobierno de Canarias GRAFCAN, Diputaciones of Navarra/Álava/Bizkaia/Gipuzkoa, Generalitat Valenciana) and the EU JRC PVGIS service to retrieve public map data. These services answer public WMS/WFS/ArcGIS requests; they receive only the queried coordinates, like any normal map pan in a GIS viewer.
Listings: On supported portals, listing coordinates already present in the page’s own API responses are read locally in your browser to run the same public geodata queries. They are not uploaded anywhere else.
Settings: Your preferences (enabled layers, opacity, panel visibility) are stored via chrome.storage.sync – they sync through your own Google account using Chrome’s built-in mechanism. The developer has no access to them.
Licence: Your licence key is stored in chrome.storage.sync (so it works on your own Chrome devices); this device’s instance id and last validation time are stored in chrome.storage.local. The developer never receives either.
Cache: Analysis results are cached in-memory per browser session only and discarded on restart.

Permissions justification

Permission	Reason
`storage`	Save user preferences (layers, opacity, panel) and licence state.
`alarms`	Periodic background licence revalidation (every 12 h while the browser runs).
`host_permissions` (gov domains)	Required to fetch public map images and feature data from the official Spanish geoservices listed above.
`host_permissions` (api.polar.sh)	Required to activate and periodically revalidate the licence key.
`content_scripts` (portal + Google Maps domains)	Required to draw the overlays and controls on the supported real-estate portals and on embedded/hosted Google Maps views they use.

Licence verification is necessary to perform the purchase contract (Art. 6(1)(b) GDPR). Only the licence key and the random device id are transmitted — no name, e-mail, browsing or location data.
Licence requests go to Polar (Polar Software Inc., merchant of record). Processing there is governed by their privacy policy; the developer receives no copy of these requests.
Everything else runs locally in your browser. Settings and licence key sync only through your own Google account via Chrome’s storage sync.

No data is sold, shared or transferred to any third party, ever — apart from the licence-verification calls described above, which carry no personal data beyond the key you were given and a random id.

Chrome Web Store Limited Use

The use of information received from Google APIs adheres to the Chrome Web Store User Data Policy, including the Limited Use requirements. The extension reads the on-page map/listing data of supported sites only to query the public geoservices described above; it does not collect, sell or transmit browsing activity, and nothing is used for advertising, credit-worthiness or any unrelated purpose.

Contact

For questions, open an issue on the project page linked in the Chrome Web Store listing.