Alby96andClaude Opus 5
e14308bbb6
Scanned the two public ARPA Piemonte APIs and recorded what they actually contain, so this question does not get re-litigated from the marketing pages later. Neither needs a key, a token or a registration. This corrects something I got wrong. The docs said ARPA states no licence for its data, based on the open-data page saying only "gratuiti". The site's legal notice does state one — CC BY 4.0, commercial use explicitly permitted, credit "Fonte: Arpa Piemonte - www.arpa.piemonte.it" — and both APIs link that notice from their OpenAPI description, so anything they serve is covered. Only the radar volumes remain ambiguous, because their own page does not repeat the licence and the access link is still issued by email; both questions belong in the same message to ARPA. The survey's operative findings: - api_realtime carries 374 stations with coordinates, of which 286 have a rain gauge, spanning 74 m to 2820 m of elevation. - Its observations lag by about 4.5 hours on an hourly cadence, measured uniformly across every station sampled. That is the property that decides how it can be used: it is an observation archive with a publishing delay, not a real-time feed, and it must never sit next to 5-minute radar looking current. - Only 4 of 143 hydrometer stations publish guard and danger thresholds, and 5 publish a river name. A river-level warning built on this would be empty for 97% of stations, so that idea is recorded as rejected rather than pending. - Meteoweb is a 3.27-million-record historical archive plus a seismic catalogue: a research dataset, not app content. One thing is worth adopting: rain-gauge accumulations as ground truth for the radar. Radar infers rainfall from reflectivity aloft, gauges measure what reached the ground, and the network is densest exactly where Alpine terrain blocks the beam. It belongs behind the worker, clearly timestamped, once the worker exists. Also notes that the credit ARPA asks for is the full "Fonte: Arpa Piemonte - www.arpa.piemonte.it", not the bare name currently in the region config, to be adopted the moment any ARPA-sourced data is displayed. No code changes: nothing is integrated yet. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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Licenses and attribution obligations
Nuvolari redistributes third-party data. Every obligation below is binding: the Sources screen in the app must satisfy all of them, and none of them may be dropped to save screen space.
Summary
| Data | License | Mandatory credit | Notes |
|---|---|---|---|
| Radar-DPC rasters | CC BY-SA | "Radar-DPC" | Share-alike propagates to our frames |
| ARPA Piemonte data | CC BY 4.0, commercial OK | "Fonte: Arpa Piemonte - www.arpa.piemonte.it" | Radar volumes: licence not repeated on their page, access by email |
| ARPA Piemonte alerts | CC BY 4.0 (site notice) | as above, + link to the official bulletin | Levels republished verbatim |
| OpenStreetMap data | ODbL | "© OpenStreetMap contributors" | Must stay visible on the map |
| OpenMapTiles schema | BSD 3-Clause | "© OpenMapTiles" | Must stay visible on the map |
| OpenFreeMap service | MIT | "OpenFreeMap" — optional | Listed on the Sources screen |
Share-alike is the constraint that shapes the backend
The Radar-DPC rasters are CC BY-SA. The PNG frames the worker produces — cropped, reprojected, colourised — are a derived product, so they inherit CC BY-SA. Practical consequences:
- The published frames and
manifest.jsonare CC BY-SA and must be labelled as such. - We cannot relicense them, and we cannot restrict their reuse.
- The share-alike obligation covers the data, not the app's source code or UI.
The manifest carries its own attribution string for exactly this reason: the credit
travels with the frames rather than being remembered at render time, and the app
displays whatever the publisher of those frames says to display.
ARPA Piemonte: CC BY 4.0, stated in the legal notice
ARPA's legal notice at https://www.arpa.piemonte.it/note-legali releases environmental and open data under CC BY 4.0, explicitly permitting commercial use, and requires the credit "Fonte: Arpa Piemonte - www.arpa.piemonte.it". Logos, institutional emblems, registered trademarks and third-party content are excluded.
Both ARPA REST APIs — api_realtime and Meteoweb — link that notice from their OpenAPI
description, so anything served by them is covered without further correspondence.
The radar volumes are the one gap: their open-data page says only gratuiti and does not repeat the licence, and the real-time access link is issued by email. Ask ARPA to confirm both in the same message. Until then the radar adapter stays disabled — see data-sources.md section 2.
The credit string ARPA asks for is the full "Fonte: Arpa Piemonte - www.arpa.piemonte.it", not the bare name currently in the region config. Adopt the full form the moment any ARPA-sourced data is actually displayed.
Base map credits are not automatic
The OpenFreeMap style JSON has no attribution field, so MapLibre displays nothing on
its own. The app renders the credits itself:
- the always-visible attribution bar carries the two mandatory credits;
- the Sources screen lists all three with their licences and links.
The bar lists only what is actually on screen. With the offline fallback style there is no OpenStreetMap data being displayed, so crediting OpenStreetMap there would be a false attribution — the bar says "Mappa base non configurata" instead.
Advertising, and why it still matters here
The app currently carries no advertising, so it is not a commercial product today. Ads are a plausible future, though, and a source adopted now on non-commercial terms would have to be ripped out then. Prefer sources that permit commercial use.
This is why Open-Meteo's free tier and Blitzortung remain listed as excluded even though the features that would have used them are out of scope: both are non-commercial-only, and neither should be reached for on the grounds that there are no ads at the moment.
Naming and independence
The app must never appear to be an official ARPA or Protezione Civile product:
- no ARPA/DPC logos, coats of arms or institutional branding;
- never the word "ufficiale" applied to the app itself (the bulletin is official — the app is not);
- the Sources screen carries an explicit disclaimer that Nuvolari is an independent app, not affiliated with, endorsed by, or operated by ARPA Piemonte or the Dipartimento della Protezione Civile;
- for civil-protection purposes the official channels always prevail, and the app says so next to every alert.