capy Privacy Policy

Effective date: 21 September 2026 · 中文版

This Privacy Policy explains how the capy application accesses, uses, stores and shares your data, including the Google user data capy can access after you sign in with Google and grant consent, and how you can revoke access and delete your data.

1. What this policy covers

This policy applies to the capy application (the command-line tool and its built-in local web interface, capy --web) and to this website, capy.taislife.work. capy is maintained by Tai (GitHub: Tai-ch0802) as an individual. The source code is public on GitHub under the MIT License, so every statement below can be verified in the code.

2. Google user data capy accesses

Signing in with Google is optional. When you run capy auth login google and grant consent, capy requests exactly the following three scopes and no others:

• openid: identifies which Google account signed in.
• https://www.googleapis.com/auth/userinfo.email: the email address of that account.
• https://www.googleapis.com/auth/drive.appdata: read and write files that capy itself creates in the application data folder (appDataFolder) of your Google Drive. This scope cannot read, list or modify any other file in your Drive.

3. How that data is used

• Your email address is used only to show which account is signed in (capy auth status), so that you can notice if you signed in to the wrong account. capy never emails you and does not use the address for anything else.
• The application data folder stores what is needed to keep playlists in sync across your devices: playlists (name, description, tracks and their order, and which service playlists they are linked to), track data (title, artist, album, duration, ISRC, and the track's ID on each music service; if you connect a music folder on your computer, that "ID" is the file's path relative to that folder, and a local playlist's ID is "device ID/playlist file name", so paths and file names you chose yourself may be included), a device list (a random ID capy generates for each computer, the computer's name, and the last sync time), and a per-device snapshot of what each playlist looked like at the last sync.
• capy does not use Google user data for advertising, does not use it to train any AI or machine-learning model, does not build user profiles, and does not use it for any purpose other than those described in this section.

4. Where data is stored

• Your Google Drive (application data folder): the sync data listed in section 3. It counts against your Drive storage, is not visible in the Drive interface, and cannot be shared with anyone.
• Your computer: a local cache of the same data (an SQLite file); a settings file (which includes the email address above); and access tokens for Google, Spotify and Apple Music, which are stored only in the operating system keychain (macOS Keychain or Windows Credential Manager), never in settings files, the database, or Drive.
• On our side: nothing. capy has no backend server, no account system, and no telemetry or crash reporting. The program connects only to the services you use (Google, Spotify, Apple); when a capy --web page shows album art or plays a preview, your browser loads those images and audio files directly from Spotify's or Apple's content servers. Apart from that, capy contacts GitHub only when you run capy update, to check for and download a new version (capy update --dev instead has the Go toolchain on your computer download the source code from GitHub and the Go module proxy).

5. Sharing and transfer

capy does not share, transfer, sell or disclose your Google user data to any third party, including us: the data never leaves your computer and your own Google account. When you sync or transfer a playlist, capy sends public identifiers of the tracks (such as ISRC, title and artist) to the music services you are signed in to, at your direction, to look songs up or add them to a playlist. That is data about the music, not your Google user data.

capy's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.

6. Retention and deletion

Because the data is in your hands, you decide how long it is kept. To remove everything:

• Revoke access: remove capy under Google Account → Third-party apps and services.
• Delete the data in Drive: Google Drive → Settings → Manage apps → capy → "Delete hidden app data".
• Delete the data on your computer: run capy auth logout google to clear the tokens from the keychain, then delete capy's settings folder (macOS: ~/Library/Application Support/capy-music; Windows: %AppData%\capy-music).

7. Security

All connections between capy and Google, Spotify and Apple use HTTPS. Tokens are stored only in the operating system keychain. The capy --web interface binds only to 127.0.0.1 (reachable only from your own computer), uses a one-time access code on every start, and never shows any token or secret on the page.

8. This website

capy.taislife.work is a static website: it sets no cookies, loads no third-party resources, has no forms, and contains no analytics or tracking code of our own. It is hosted by Cloudflare, and the hosting provider may automatically add analytics code to pages at the domain level. This site's Content Security Policy (default-src 'none') forbids pages from running or loading any script; in our tests that code is blocked by your browser and is neither executed nor loaded.

As with any website, Cloudflare processes the technical information needed to serve a request (such as IP addresses and the headers your browser sends with the request) under its own privacy policy. Our Cloudflare account may keep access logs (the requested URL, the time, and the technical information above) for a limited period, solely to troubleshoot the website; we do not use those records to identify or track visitors. This site shares its parent domain with taislife.work: if you have visited other pages on taislife.work, your browser may include cookies set by those pages in the request headers it sends to this subdomain. Like any other header they reach the hosting provider and are covered by the previous sentence; nothing on this website reads or uses them, and we never look at them.

9. Children

capy is not directed to children under 13, and we do not (and cannot) collect personal data from anyone.

10. Changes to this policy

If the way capy accesses data changes (for example, a new permission), we will update this page and the effective date above before releasing the new version. Every revision is kept in this file's version history.

11. Contact

Questions about this policy or your data: please open an issue on GitHub Issues (do not paste tokens or personal data into a public issue).