Privacy

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What this page covers

This page describes what information Cards4 collects, how that information is used, who else sees it, how long it is kept, and what choices you have. If something is not mentioned on this page, Cards4 is not doing it. If you spot a gap, that is a bug — the source repository is the right place to report it.

Information Cards4 collects

If you do not sign in: Cards4 issues your browser a guest session token so the game server can route channel messages back to you. The token is a random identifier, not tied to any personal data, and lives in an HTTP-only cookie with a 90-day sliding expiry so your local game progress survives browser restarts.

If you sign in: Cards4 stores the email address you gave us, an optional display name and username, your card-theme preferences, the times the account was created and last updated, an internal admin flag, and a per-account identifier. That is the entire user record. Cards4 does not store a password because Cards4 does not use passwords — authentication is a single-use magic link sent to your email.

Analytics: Cards4 runs a self-hosted instance of Plausible at tracking.teetrack.it. It is loaded only after you grant consent via the cookie banner. Plausible collects: the page URL you visited, the referrer URL, the day, the country (derived from IP, never stored), the browser, and the operating system. It does not set cookies, does not store the raw IP address, and does not build a per-visitor profile.

Error reports: When something breaks, Cards4 sends an error report to Sentry so the bug can be fixed. The report contains a stack trace, the browser version, and a short breadcrumb trail of what the application was doing. Personally identifying information (email addresses, user identifiers, raw request bodies, cookies) is scrubbed before the event leaves your browser or the server.

How that information is used

  • The email address is used to send you a sign-in link when you ask for one, and only for that.
  • The session and account identifiers are used by the game server to route real-time events to the right browser tab.
  • Analytics is used to understand which pages get used and which do not — aggregate counts, not per-person funnels.
  • Error reports are used to fix bugs. They are not used for any marketing or product-decision purpose.

Cards4 does not sell data, does not rent data, and does not share it with advertising networks. Cards4 has no advertising networks or tracking pixels.

Third parties

Two third-party processors are in the chain: the SMTP provider used to deliver the magic-link emails, which sees the destination email address and the body of the email but not your game activity, and Sentry (sentry.io), which receives the scrubbed error reports described above. Plausible is self-hosted, so no third party is involved in analytics.

Your rights and choices

If you have an account, you can:

  • Export your data. The data settings page gives you a JSON file containing everything on your account record.
  • Delete your account. Typing your email to confirm from the settings page immediately and irreversibly anonymizes your record: the email address, display name, and username are removed, all sessions are revoked, and friendships, ratings, leaderboard entries, and replays are deleted. An anonymized tombstone row remains so shared match history stays consistent, but nothing on it can identify you.
  • Withdraw analytics consent. The cookie banner is available on every page. Revoking consent stops the Plausible script from being loaded on subsequent page views.

This document does not claim compliance with any specific data protection regime (GDPR, CCPA, or otherwise) because that claim has not been legally reviewed. The behaviour described here is what Cards4 does in practice.

Retention

Guest cookies expire 90 days after your last visit, and the token they carry is not persisted server-side beyond what is needed to route channel messages and keep your game state. Account records persist until you delete them, or until the server is decommissioned. Magic-link tokens are single-use — a consumed link is invalidated the moment it is used — and expire automatically after 15 minutes if unused. Analytics events live for as long as the Plausible instance retains them (default: indefinitely, in aggregate form). Sentry events are retained for Sentry's standard retention window (90 days at the time of writing) and then deleted.

Cookies

Cards4 sets up to two cookies without consent, both HTTP-only, SameSite-Lax, and not readable from JavaScript: the session cookie that keeps you signed in, and — when you are not signed in — a guest cookie holding a signed random token (90-day sliding expiry) so the game server can route messages back to you. Neither contains personal data. No other cookie is set even if you grant analytics consent: the analytics provider (Plausible) does not set cookies.

Changes

When this document changes in a material way, the “Last updated” date at the top of the page will change too. If you have an account, no separate email notice is sent — checking back here is the canonical source.

YouTube videos

Game and guide pages contact YouTube only when you play a video. Dedicated watch pages under /videos load a YouTube privacy-enhanced player when opened, without autoplay. YouTube receives your IP address and browser information when its player loads, and may use cookies or other storage when you play. YouTube controls the player and any advertising it displays. These requests are separate from your Cards4 analytics choice. You can read guides and play the card games without opening a video.

Google / YouTube