MCU App

This policy explains what cookies and browser storage MCU App uses, why, and how you can control them. It works alongside our Privacy Policy.

Cookies

MCU App sets two cookies, both first party and both strictly necessary — they carry your sign-in state so the server can render the page already signed in, instead of the header flashing on every load. Strictly necessary cookies don't require consent under GDPR. There are no third-party cookies.

mcu_user — your account ID, so the server knows you're signed in. Duration: 1 year, or until you sign out or delete your account, whichever comes first. First party.
mcu_user_name — your display name, so your name renders without a round trip. Duration: 1 year, or until you sign out or delete your account, whichever comes first. First party.

Session storage

Held in sessionStorage, which is per browser tab. All of it is deleted the moment you close the tab.

mcu_user, mcu_user_name — a per-tab copy of the sign-in state above. Duration: until the tab closes.

Local storage

Held in localStorage. This is an on-device cache of data that also lives in your account, so the app can paint instantly instead of waiting on the network. It has no expiry date and persists until you clear it — via your browser's site-data controls, or automatically when you delete your account in Settings. Entries ending in <you> are per account.

If you track titles without an account, the mcu_guest_* entries are not a cache: they are the only copy of that progress, kept on this device and sent nowhere. Signing up or logging in copies them into your account (you're asked first when it's an existing one) and then removes them. Some browsers clear this storage on their own, for example after a period without a visit, so it can't be relied on to last.

mcu_cookie_consent — remembers the choice you make in the cookie banner, so you aren't asked again.
mcu_guest_watched_v1 — signed out: the titles you've marked as watched on this device.
mcu_guest_episodes_v1 — signed out: the episodes you've ticked off on this device.
mcu_guest_prompts_v1 — signed out: which progress milestones you've already been shown, so they appear once.
mcu_guest_merge_v1 — whether you chose to add this device's progress to an account, so you're only asked once.
mcu_watched_<you> — which titles you've marked as watched.
mcu_ep_<you>_<show> — which individual episodes of a show you've ticked off.
mcu_guide_progress_<you>_<guide> — your position in a watch guide.
mcu_ratings_<you> — the ratings you've given titles.
mcu_badges_v3_<you> — the badges you've earned.
mcu_settings_<you> — your app preferences.

Third parties

No third party sets a cookie through MCU App, and there are no advertising or social media trackers anywhere in the app. Three external services are involved in running it:

Google Firebase — handles sign-in. It stores your authentication token in your browser's IndexedDB (not a cookie), where it stays until you sign out.
The Movie Database (TMDB) — poster images load from TMDB's CDN, so your IP address is visible to TMDB. It sets no cookies for us.
Vercel — hosts the app and keeps standard server access logs. Vercel Web Analytics also counts page views and referrers, without cookies and without storing anything on your device.

See our Privacy Policy for how these services handle your data.

Non-essential (analytics)

There are none today. The one analytics tool in use, Vercel Web Analytics, is cookieless — it sets nothing on your device, so there is no non-essential cookie to consent to. If a cookie-based analytics tool is ever added, its cookies will stay off until you explicitly opt in via the cookie banner or the preferences link in the footer — never on by default.

Managing your choice