Privacy Policy of Nucube

Nucube (“we”, “our”, or “the App”) is a cross-platform player for the music you own, available on Linux, macOS, Windows, Android, and iOS. This Privacy Policy explains what the App keeps on your devices, what it sends over the internet, and why. It applies to Nucube 0.14 and later, and to the email news you can subscribe to on our website.

1. Our Privacy Philosophy

We believe that your music library and your listening habits are private. Nucube is a local utility: it plays the files you already own, from the folders, shares, and devices you control. There is no Nucube server to run and no cloud locker — we never host your music. The App has no ads and no discover feed, and requires no account. If you allow it, it sends usage statistics and error reports that help us fix bugs and improve it: both are off by default, section 2 explains exactly what they contain, and section 4 lists every internet feature.

2. What the App Collects and Sends

   Personal Information: Nucube has no accounts. The App does not ask for your name, your email address, or other contact details.

   No Data About You or Your Music: Apart from the optional internet features described in section 4, the App sends no information about you or your music library. Usage statistics contain no track, artist, or album titles, nothing about the contents of your library, no file paths, and no names of your devices or renderers. Error reports are designed to leave out the same information (see below). Your audio files are never sent.

   Off by Default: Usage statistics and error reports are two separate choices, and both are off by default. The App sends neither unless you give your consent. If you update from an earlier version, the App asks you once, and nothing is sent until you answer.

   Usage Statistics (Telemetry): What: the App version; your platform and operating system; which features and screens of the App are used (screens are recorded by type, without any identifier of the album, artist, or track shown); technical details of playback, such as the kind of source (for example a local folder, SMB, NFS, or DLNA), the kind of renderer, the audio format, the approximate track duration, and whether playback worked; and an approximate location, such as the country, that PostHog may derive from the IP address of the connection. Usage statistics contain only these categories of data. Each event carries a random identifier that the App creates when it is installed. It is not derived from your hardware and is not linked to your name or your email address. Because this identifier links events from the same installation, usage statistics are pseudonymous personal data. Purpose: to understand how the App is used and on which platforms, so that we can decide what to improve. When: only if you agree, on the consent screen shown at first launch or later in Settings; a change takes effect immediately.

   Error Reports: What: the type of error and its message, the App version and platform, and the most recent lines of the App’s internal log. Reports carry no persistent identifier. Before sending, the App cleans those log lines: file paths are replaced by the kind of source and the file extension, names of shares and shared folders are removed, and so are links, credentials, and other sensitive identifiers. Even so, in rare cases a log line may still contain technical details about your setup, such as the address or name of a device on your local network, so we treat error reports as personal data. Purpose: to find and fix bugs and crashes. When: only when you choose to send a report with the button shown next to the error. After your first report, the App asks you once whether to send future reports automatically; you can change that answer at any time in Settings.

   Where It Goes: Usage statistics and error reports are sent to PostHog (EU cloud) and Axiom (EU region), which process them on our behalf (section 6). We do not use them for advertising and we do not sell them.

   Your Choice: You can withdraw your consent at any time by turning usage statistics or automatic error reports off in Settings. From then on nothing more is sent; withdrawing does not affect the lawfulness of what was sent before. If you would like past usage statistics deleted, write to daniele@nucube.music: since we do not know who you are, we will work with you to identify the data from your installation and delete it. Because error reports carry no identifier, we may not be able to single out a specific report.

   Advertising: Nucube is 100% ad-free. No data is shared with advertising networks.

3. What Stays on Your Devices

   Audio Files: Your music stays where it is — on your NAS, your computer, your phone or tablet, or any other device. Nucube plays files from your folders and shares; they are never uploaded to us.

   Library Database: The artist, album, and track library lives in a database on your devices.

   Downloaded audio: If you choose to download audio files onto a device for offline listening, those are copies you asked for. The originals stay put.

4. Network Use

   Local Network: Playing from filesystem folders, SMB, NFS, or DLNA sources, and sending playback to UPnP or OpenHome renderers, happens on your local network.

   Internet — Music Metadata: Nucube may query the MusicBrainz public database and the Cover Art Archive to match and enrich album and artist metadata and covers. Those are read-only lookups about music — not a listening profile — and they go to MusicBrainz, not to us.

   Internet — Lyrics: When you open the lyrics panel, the App sends the artist and title of the current track directly from your device to LRCLIB (lrclib.net), a public lyrics database, to find the lyrics. This request does not go through Nucube: we never receive it.

   Internet — Updates: On desktop, the App checks nucube.music for new versions. Like any web request, this reveals your IP address and the App version to the server that hosts nucube.music.

   Internet — Feedback: If you send feedback from the App, we receive your message together with an app identifier, the App version, your platform, and your language; on Linux a screenshot is attached automatically. Feedback reaches us through Telegram.

   Internet — Recommendations: An optional recommendations feature, off by default, sends information about music to nucube.music, which uses an external AI model to generate suggestions.

   Internet — AI Model Download: Some features download an AI model file from Hugging Face; the download reveals your IP address to Hugging Face.

   Internet — Experimental Features: An experimental section of the App can connect to public Nostr relays.

   Internet — Usage Statistics and Error Reports: Only if you allow them; sent to PostHog and Axiom as described in section 2.

   Pair / Sync: When you pair on the local network, the desktop sends its library (artists, albums, tracks) to your mobile device and overwrites the copy on the mobile device. That exchange goes between your devices, not to Nucube. Sync is the library metadata, never the audio files.

5. App Permissions

Nucube asks for access only for the jobs described above, on every platform — Linux, macOS, Windows, Android, and iOS:

Network Access: To discover and reach the music sources on your local network and to send playback to UPnP / OpenHome renderers.

Storage Access: To play, and if you choose to download, audio files that live on the device itself.

Internet Access: Used for the internet features listed in section 4 and, if you allow it, to send the usage statistics and error reports described in section 2.

6. Third-Party Services

These are the services the App and the website’s email news talk to. “Acts for us” means the service handles the data only on our instructions (a processor). “Independent” means your device contacts a public service directly, or the service decides for itself how to use what it receives (an independent controller): its own privacy policy applies. There are no social media or advertising SDKs in the App. We do not sell data and we do not share it with advertisers.

PostHog — usage statistics and error reports (section 2). When: only if you give your consent; both are off by default. Role: acts for us (processor). Location: PostHog Inc., United States; the data is stored on its EU cloud in Frankfurt, Germany.

Axiom — usage statistics and error reports (section 2). When: as for PostHog. Role: acts for us (processor). Location: Axiom, Inc., United States; the data is received, stored and queried in its EU edge deployment (AWS eu-central-1, Frankfurt, Germany).

Netlify — hosts nucube.music, including the update check and the server that forwards your feedback. Receives your IP address and the content of each request (for example the App version when checking for updates, or your feedback). When: the update check runs automatically on desktop; feedback only when you send it. Role: acts for us. Location: Netlify, Inc., United States.

Telegram — our server delivers the feedback you send to a private Telegram chat through the Telegram Bot API. Receives your message, the app identifier, App version, platform, language and, on Linux, the screenshot. When: only when you send feedback. Role: the messaging service we use to receive feedback; Telegram also handles these messages under its own privacy policy. Location: Telegram is based outside the EEA (group companies in the British Virgin Islands and Dubai); its privacy policy says data of accounts registered in the EEA is stored in the Netherlands.

Resend — sends the website’s email news. Receives your email address and delivery information about the emails we send you. When: only if you subscribe on the website. Role: acts for us. Location: Plus Five Five, Inc. (Resend), United States.

MusicBrainz — album and artist lookups. Receives the search (such as album and artist names or MusicBrainz identifiers) and your IP address; MetaBrainz says it keeps IP addresses in its web logs for 7 days. When: the feature is on by default; lookups run when you match or enrich albums. Role: independent public service, contacted directly by your device. Location: MetaBrainz Foundation, a non-profit based in California, United States.

Cover Art Archive — album covers. A joint project of MetaBrainz and the Internet Archive; the images are stored on Internet Archive servers. Receives the identifier of the release and your IP address. When: together with MusicBrainz lookups. Role: independent public service, contacted directly by your device. Location: United States.

LRCLIB — lyrics. Receives the artist and title of the current track and your IP address, directly from your device; we never receive the request. When: only when you open the lyrics panel. Role: independent public service. Location: an independent, volunteer-run open-source project.

Recommendations — optional, off by default. Sends information about the music involved to nucube.music, which forwards it to an external AI model provider to generate the suggestions. When: only if you turn the feature on. Role: the request is handled for us; the AI provider receives it to generate the suggestions.

Hugging Face — download of an AI model file. Receives your IP address and the download request. When: only when a feature needs the model. Role: independent service, contacted directly by your device. Location: Hugging Face, Inc., United States (its privacy policy says its servers are in the United States; its EU establishment is Hugging Face SAS in Paris, France).

Nostr Relays — the experimental section of the App. Public relays such as relay.damus.io, nos.lol and relay.primal.net receive your IP address and what that section sends or asks for. When: only if you use that section. Role: independent operators. Location: the relays are run by independent operators in various countries.

Website: When you visit nucube.music, our hosting provider (Netlify) processes technical data about your visit, such as your IP address and the pages requested, in its standard server logs; it acts for us as our hosting provider. The website also measures visits with two cookieless analytics tools, Umami Cloud and PostHog: they set no cookies and keep no persistent identifier on your device, so no consent banner is needed. The only thing the website may keep on your device is the campaign tags of the link you arrived from: if you arrive through a link with campaign tags (utm_*), the site keeps those tags in your browser’s session storage for that tab only, to know which campaign brought you. It is not a cookie, it is deleted when you close the tab, and it does not identify you across visits. Umami Cloud (Umami Software, Inc., United States) records aggregate page statistics. PostHog (section 6) records page views, outbound-link and file-download clicks, and, if you subscribe to the email news, the fact of that subscription; because PostHog keeps its session identifier in memory only, those events are not linked to a profile of you across visits. Neither tool is part of the App.

7. Files We Never Write

Nucube reads tags to build its library database, but it never writes back to your files. We do not move, rename, or rewrite your collection, and we never write tags, cover art, or metadata into your audio files. If you stop using Nucube tomorrow, your collection is unchanged.

8. Data Controller

   Who We Are: The data controller for the personal data described in this policy is Daniele Dellafiore, a natural person based in Italy, who develops Nucube.

   Email: daniele@nucube.music

9. Why We Use Data and on What Legal Basis

   Usage Statistics (section 2): To understand how the App is used and decide what to improve. Legal basis: your consent (Art. 6(1)(a) GDPR). Storing the installation identifier on your device and reading it back also requires your consent under Art. 122 of the Italian Privacy Code (Legislative Decree 196/2003), which implements Art. 5(3) of the ePrivacy Directive (2002/58/EC). We ask for both on the consent screen, and you can withdraw them at any time (section 2, Your Choice).

   Error Reports (section 2): To find and fix bugs and crashes. Legal basis: your consent (Art. 6(1)(a) GDPR), which you give each time you send a report or, if you choose, once for automatic reports, and which you can withdraw at any time (section 2, Your Choice).

   Features You Use (section 4): When you use a feature that contacts an online service (MusicBrainz and the Cover Art Archive, LRCLIB, recommendations, the AI model download, or the experimental Nostr section), the request is sent to provide the feature you asked for (Art. 6(1)(b) GDPR). Except for recommendations, these requests go from your device straight to those services; we do not receive them.

   Feedback: To read and answer the feedback you send us and to improve the App. Legal basis: our legitimate interest in handling the messages you choose to send us (Art. 6(1)(f) GDPR).

   Updates: On desktop, to tell you when a new version is available. Legal basis: our legitimate interest in keeping the App up to date and secure (Art. 6(1)(f) GDPR).

   Email News (website): If you subscribe on the website, we use your email address to send you news about Nucube by email. Legal basis: your consent (Art. 6(1)(a) GDPR), which you can withdraw at any time by writing to us.

10. How Long We Keep Data

    Usage Statistics: We keep them only as long as they are useful to understand how the App is used and how this changes between versions, then we delete them.

    Error Reports: We keep them only as long as needed to analyse and fix the problems they describe, then we delete them.

    Feedback: We keep your messages as long as needed to read them, answer you, and act on them.

    Update Checks: The server logs of nucube.music are kept by our hosting provider according to its standard log retention.

    Email News: We keep your address while you are subscribed and remove it after you unsubscribe.

    Data on Your Devices: The library database and your settings stay on your devices and under your control; we never receive them.

    Other Services: Requests your device sends directly to the services in section 4 are kept according to those services’ own policies.

11. Recipients and Transfers Outside the EU

    Recipients: The services that receive data, with their role and location, are listed in section 6.

    Transfers Outside the EU: Usage statistics and error reports are stored in the EU (section 6). Some services that act for us are companies based in the United States: PostHog, Netlify and Resend state that they are certified under the EU-U.S. Data Privacy Framework, which the European Commission recognises as ensuring adequate protection (adequacy decision of 10 July 2023); Resend’s and Axiom’s data processing terms also include Standard Contractual Clauses. Feedback delivered through Telegram and, if you turn them on, recommendations may also be processed outside the EU, under those providers’ own terms. The independent services your device contacts directly (MusicBrainz, Cover Art Archive, LRCLIB, Hugging Face, Nostr relays) may be located outside the EU, and their own policies apply.

12. Your Rights

    Your Rights: Under the GDPR you have the right to access your personal data and get a copy of it, to have it corrected if it is wrong, to have it erased, to restrict how it is used, to receive it in a portable format, and to object to its use when it is based on our legitimate interest. Where the legal basis is your consent, you can withdraw it at any time; this does not affect what was done before you withdrew it.

    How to Exercise Them: Write to daniele@nucube.music. We will reply within one month. Because the App does not know who you are, we may need your help to find the data linked to your installation.

    Complaints: You can lodge a complaint with the Italian data protection authority, the Garante per la protezione dei dati personali (www.garanteprivacy.it), or with the data protection authority of the EU country where you live or work, or where you believe the infringement took place.

13. Children

Nucube is not directed at children under 14. In Italy, 14 is the age from which a person can consent on their own to online services (Art. 2-quinquies of the Italian Privacy Code). If you believe a child under 14 has sent us personal data, for example through feedback, write to us and we will delete it.

14. Automated Decisions

We do not take decisions about you based solely on automated processing, including profiling, that have legal or similarly significant effects on you. The optional recommendations feature only suggests music and has no such effect.

15. Changes and Contact

We may update this Privacy Policy from time to time as we add features. Any changes will be reflected by the date at the top of this page.

If you have questions about privacy while using the App, or about our practices, please email us at: daniele@nucube.music