Chelys
Privacy policy
Chelys plays music files stored on your own device. It has no accounts, no ads and no analytics. Your library, playlists, likes, listening history and settings stay on your device. Chelys always looks up lyrics on LRCLIB, sending the title, artist, album and length of the track you are playing. Everything else it sends over the internet happens only if you turn it on: requests to your own music servers, online artwork lookups, and scrobbles to Last.fm or ListenBrainz.
Who makes Chelys
Chelys is made by an individual developer resident in India, not by a company. That developer is responsible for this policy and for Chelys on Android and Mac. Questions about privacy go to privacy@shutbox.im.
What stays on your device
Chelys keeps all of this in its own storage on your phone or Mac. None of it is uploaded, and the developer has no access to it.
- Your music library: the folders you choose, and the tags, artwork and length of each track.
- A fingerprint of each track, computed from its audio, so your likes and lyrics stay with a track after you retag or move it.
- Your likes and when you made each one, your playlists and when each was created and last changed, hidden albums, equalizer profiles and settings.
- Lyrics Chelys has already downloaded.
- Your listening history on Android: each song you play, when, for how long, whether you skipped it, and which song came before it. Chelys keeps your latest 50,000 plays. Autoplay's "Songs like this" uses them to pick what to play when your queue ends.
- If you add a music server on Android: its address and your user name; for a Subsonic server your password, and for Jellyfin or Emby the sign-in token the server gives back instead of your password, either one encrypted with a key kept in Android's keystore; plus copies of songs you played from it, up to the limit you set in Settings › Storage.
- If you turn on online artwork: the covers and artist photos it finds or you pick.
- If you connect Last.fm or ListenBrainz: the sign-in key it gives Chelys, encrypted the same way, and plays waiting to be sent while you are offline.
- Details of your audio output, such as your USB DAC's name, sample rates and volume range, read so Chelys can play through it.
- Skins you make or add: their colours, corners, font names and layouts.
What leaves your device: lyrics
When a track starts, Chelys looks up its lyrics on LRCLIB, a free, open lyrics database. It also looks up the next track in your queue, so its lyrics are ready when it starts. Each lookup sends:
- the track's title, artist, album and length, taken from the file's tags
- the app's name and version, such as
Chelys/0.1.0 (Android music player)
Lookups use HTTPS. Like any server, LRCLIB sees your device's IP address. Chelys sends no account, advertising ID, device ID or anything else that identifies you. Lyrics that are found are saved on your device, so each track is looked up once. LRCLIB is run independently of Chelys; see lrclib.net for how it handles requests.
Chelys has no setting to turn lookups off. To stop them, use Chelys offline or turn off its network access in your device's settings, where your device offers that. Playback never needs the internet.
What leaves your device: your music servers
On Android you can add a music server that you or someone you trust runs: a Subsonic-compatible one such as Navidrome, a Jellyfin server or an Emby server. Chelys then talks to that server only, at the address you enter. It asks for your music libraries, albums, artists and covers, and streams the original files of the songs you play.
- Subsonic: each request carries your user name, a one-time token made from your password, and the app's name. Your password itself is never sent.
- Jellyfin and Emby: your password is sent once, to sign in, and the server gives back a token that Chelys uses from then on. Jellyfin's Quick Connect signs in with a code instead of a password. Each request carries the app's name and version, your phone's model name, such as
Pixel 8, and a random ID Chelys makes for that server, which the server uses to list the devices signed in to your account.
Chelys also tells the server which song is playing and, once you have heard it, that you played it and when, so the server's own play counts and history stay current. You can stop this for each server, or for everything, in Settings › Scrobbling.
That server sees which songs you browse and play, as any music server does; its owner's policy applies. Chelys sends nothing about your server or its music to the developer or anyone else.
What leaves your device: online artwork
Online artwork is off until you turn it on in Settings › Online artwork. It finds covers for albums that have none and photos of artists. To do that, and whenever you search for a cover or photo yourself, Chelys sends an album's title and artist, or an artist's name, to MusicBrainz, the Cover Art Archive, Deezer and Apple's iTunes Search. If you enter your own key for fanart.tv or TheAudioDB, it asks them too, with that key. Each request carries the app's name, version and a link to its source code. By default it waits for Wi-Fi. Each of these services is run independently of Chelys, and its own policy applies.
What leaves your device: scrobbling
If you connect Last.fm or ListenBrainz in Settings › Scrobbling, Chelys sends each song you finish to your account there: its title, artist, album, album artist, length, track number and the time you started it. Songs of 30 seconds or less are not sent. Unless you turn it off, Chelys also shows the song playing now on your profile. ListenBrainz also receives the app's name and version. You connect Last.fm by signing in on its website; Chelys never sees your Last.fm password. For ListenBrainz you paste your user token, and you can enter the address of another ListenBrainz server. What you send is kept by that service under its own policy.
Skins and skin links
Skins and skin links never reach a server. When you share a skin, Chelys makes a link, a QR code or a file. The link carries the whole skin after its #, the part of a web address that browsers never send to a server, so sharing uploads nothing.
The skin designer at chelys.shutbox.im/skins runs in your browser. The skin you make there is kept in your browser's own storage, and a skin link opened there is read in your browser. The page sends no skin, link or file to this site or anyone else.
Links that open your browser
The equalizer links to autoeq.app, where you can find profiles for your headphones. It opens in your browser, and that site's own policy applies. Chelys sends it nothing. "Design on a computer" in Appearance opens the skin designer described above.
Permissions on Android
- Internet: used only for the lyrics lookups and the services you turn on, described above.
- Folder access: Chelys reads only the folders you pick with Android's folder picker. You can remove that access at any time in Android's settings.
- USB: Android asks you before Chelys can use a DAC you connect.
- Notifications: playback controls and your DAC's volume.
- Camera: only to scan a skin's QR code, and only after you tap Scan and allow it. The camera image is read on your phone to find the code and is never saved or sent.
- Foreground service and wake lock: to keep playing while the screen is off.
What Chelys does not do
- No Chelys account: you never sign up with the developer.
- No ads, analytics or tracking.
- No crash reporting or other third-party code that collects data.
- Your data is never sold or shared.
Google Play and backups
If you install Chelys from Google Play, Google may collect crash and performance data under Google's privacy policy, and shows the developer crash reports that do not identify you.
If backup is turned on for your Android device, Android may include Chelys's settings and library data in your Google account backup. Google handles that backup under your account; the developer cannot see it. Backups you make of your Mac, such as Time Machine, may include Chelys's data in the same way.
Deleting your data
Everything Chelys stores is on your device. On Android, clear Chelys's storage in the app's settings, or uninstall it; Settings › Storage in Chelys also clears your listening history on its own; removing a server deletes its saved password or token, and disconnecting Last.fm or ListenBrainz deletes its key. On Mac, Chelys's settings can clear downloaded lyrics, and removing Chelys and its data from your Mac deletes the rest. The developer keeps nothing on any server. Plays you sent to Last.fm, ListenBrainz or your music server are kept by that service; delete them there.
Children
Chelys collects no personal information from anyone, including children.
Changes to this policy
If this policy changes, the new version will be posted on this page with a new effective date.