Privacy
Effective 7 July 2026
Lucii is built to need as little of your data as possible, and to keep what it does touch on your device. There are no accounts, no analytics, no advertising and no trackers — not a single third-party analytics or crash-reporting library ships in the app.
Because Lucii is about the place you are in, it does use your location — but only while you are using it, and never to build a profile. Here is exactly what leaves your device, and to whom.
What leaves your device
| Where it goes | What is sent | What that party sees |
|---|---|---|
| Our backend (api.lucii.app), then Mapbox | Your coordinates, to turn them into a place name (reverse geocoding). | Our server receives your coordinates but never logs them, and forwards them to Mapbox. Mapbox sees the coordinates but not you — the request comes from our server, not your phone. |
| Wikidata (query.wikidata.org) | Your coordinates, to find nearby people, events and places. | The query is sent directly from your device, so Wikimedia sees your IP address and the area you are looking at. No account or identifier is attached. |
| Wikipedia (wikipedia.org) | Your coordinates, to find nearby articles. | As with Wikidata: a direct, anonymous request carrying your IP address and the area. |
| Map tiles (MapTiler) | Which map tiles your current view needs — roughly which blocks are on screen. | MapTiler serves the map imagery and sees the tile requests for the area you are viewing. |
| Stays on your device | Your last map position (rounded to about 100 m) and your Codex — the discoveries you save, kept with a city name only, never the exact spot. | Nobody. This never leaves the phone except through the operating-system backup you control. |
No accounts, no identifiers
Lucii has no login. It does not create an install ID, does not use an advertising ID, and does not fingerprint your device. Requests to Wikimedia carry a fixed app label (required by their usage policy), not anything that identifies you, and our backend is reached with a shared app key that is identical for every install.
Your searches are not logged
When Lucii asks our backend to turn coordinates into a place name, the coordinates and any query text are — in the words of our own engineering rule — "location-sensitive and NEVER logged: not on success, not on error, not at debug level. Log result counts only." Your precise location is used to answer the request, then discarded.
Location precision
Requests for nearby content carry full-precision coordinates so results are accurate for where you actually are. The only location stored on your device is your last map position, deliberately rounded to about 100 metres so the app can reopen where you left off.
Your collection stays local
The discoveries you save — your Codex — are stored in a database on your device, alongside the public article content and a city-level place name (never the coordinates of where you saved it). If your operating system backs up app data (iCloud or Android backup, under your control), your Codex is included in that backup. Uninstalling the app removes it.
Subscriptions
If Lucii+ (a paid subscription) becomes available, the purchase is handled entirely by Apple, Google and our payments partner RevenueCat — we never see your card details. Their handling of that transaction is covered by their own policies; see RevenueCat's privacy policy for how subscription data is processed.
No analytics, no ads, no trackers
We do not measure you. There is no analytics library, no crash-reporting library, no ad network and no marketing pixel anywhere in the app. The only time data leaves the app on purpose beyond the requests above is when you choose to share something yourself — for example through your phone's share sheet.
Children
Lucii is a general-audience app and does not knowingly collect information from children. Because it collects no personal information at all, there is nothing to request or delete — but if you have a question, please contact us.
Questions
If anything here is unclear, email contact@lucii.app and we will answer.
Changes
- 7 July 2026 — First published.