▰ Prism

Legal notice, privacy and terms

Last updated: 19 October 2026.

Legal notice

  • Publisher of the site: the author of the Prism project, as an individual (natural person). Publication director: the author.
  • Hosting: the author's own virtual private server (VPS), rented from OVHcloud (reverse name of the server: vps-36c79ebb.vps.ovh.ca).
  • Contact: through the Contact page.

Privacy

  • The site uses no cookie, no audience measurement and no tracker, and loads no external script or font: pages, fonts and data come from this server (the one exception, the images of the Browse page, is described below). Once signed in, your browser keeps a session token in its local storage (it is not a cookie); signing out removes it.
  • Like any web server, this one records each request in an access log: date and time, requested address, response code, size, user agent and the visitor's IP address, truncated (IPv4: the last byte; IPv6: the last 80 bits). Account headers (cookie, authorization) are never written.
  • These logs are used only to run the site and protect it against abuse and attacks (legitimate interest). They are not shared, sold or analysed to follow visitors; they are deleted automatically after 30 days. The application's technical logs, which hold no IP address, rotate within 30 MB.
  • Map search sends your filters (text, key count, BPM...) to the server in the request address; they appear only in those same logs.
  • The images of the Browse page are not hosted here: your browser loads the covers of osu! sets straight from their source, assets.ppy.sh, which then sees your IP address and the fact that you look at those images (we tell the browser not to send the originating page, 'no-referrer'). Etterna packs show no image. The "Show covers" switch on the Browse page (on by default, remembered in your browser) turns them off: your browser then contacts that site no more.
  • The game checks for updates with a plain GET of the public file releases.json. Nothing else is sent: no identifier, no account, no telemetry, no list of your files. That request is logged like any other. The game's crash logs stay on your machine.
  • A Prism account keeps: the username (visible to other players), the e-mail address (never shown), a hash of the password (Argon2id, never the password), the dates of creation and last sign-in, the version of the terms accepted, your sessions (device name, dates) and a short security log (sign-ins, password changes) kept 90 days. The anti-abuse counters use a hash of your IP address, never the address, and disappear within 2 days. An account whose address is not confirmed within 3 days is deleted.
  • Scores and replays: when you play a ranked game while signed in in the game, the game server replays it to check it, then records it on this site under your account name: the map, the speed, the accuracy, the combo, the misses, the tiers, the rating, the date, and the replay of the play. These scores and replays are public: they appear in the map's leaderboard with your account name, and anyone can download the replay. They are part of your data export, leave the leaderboards as soon as you delete your account and are erased with it.
  • Game server and presence: once signed in in the game, it keeps a connection open (WebSocket, address prism.am/play) to the game server, authenticated by a token of your account. While it is open, your account name is visible to the other connected players (the list of online players, with your state: online, in a lobby or playing) and counted in the number of players online. This presence is not recorded. The game's offline mode (Settings → Online) closes that connection and sends nothing more.
  • Chat and lobbies: the messages of the global chat and of lobbies are kept only in the memory of the game server, for the time of the conversation. They are written to no database and no log, and disappear when the server restarts or the lobby ends; a recent history is shown to the players who arrive. The file of a map shared in a lobby is kept in memory for 3 minutes at most, for the lobby members only.
  • E-mails (confirmation, forgotten password) are sent through the mail provider Brevo, which therefore receives your address and the message. Nothing else is sent: no newsletter, no advertising.
  • Deleting your account removes your scores from the rankings at once and erases your data for good on the 1st of next month; database backups are kept for at most 14 more days. You can also download your data from the Account page.
  • To access the data of your account or erase it you do not have to wait: the Account page lets you download it and delete the account. For any other request, see the Contact page; after 30 days the logs no longer exist anyway.

Terms of use

The site and the game

  • The site is free and provided as is. The game stays fully usable offline, without an account.
  • Builds published here may be test builds: unstable, changed or withdrawn at any time. You use them at your own risk.
  • For each chart, the map index keeps its metadata and its notes in a compact form (ROX format), never the music, the images or the full files. Each entry credits its creator, and Download sends you to the original source (osu!, EtternaOnline). Maps belong to their creators and the music to its rights holders: this site grants no right over those works.

Mod, skin and playlist catalogue

  • A mod is published only after the author has verified it, on request (see the Contact page). A skin is published as soon as its archive passes the checks, within a limit of 2 skins per author.
  • A playlist is published only after the Prism team has reviewed it. It holds references to maps, never map files: Prism hosts no map.
  • The author of each item is always credited. They are responsible for it: this site grants no right over their work.
  • An item can be removed at its author's request, or if a problem appears.

Accounts

  • A Prism account is created on the site. It is required for online features (multiplayer, chat, rankings), and only for those.
  • Keep your password secret: the author will never ask you for it. What an account stores is described in the Privacy section, and you can delete it at any time (see below).

Acceptable behaviour

  • No insults or offensive content in chat, rooms and names (username, room name, etc.).
  • No cheating.
  • No abuse of the services: do not attack or overload them.
  • No automated scraping beyond the documented APIs and their rate limits (429 answer). Identify your program, with a way to reach you, in the user agent.

What you post

  • Chat messages are kept only in the memory of the game server, for the time of the conversation: they are not stored and disappear when the server restarts or the lobby ends.
  • No emoji. Links are banned, except to prism.am and the official sites of osu!, Etterna and Quaver, for maps and packs.
  • You are responsible for what you write.

Moderation

  • If the rules are broken: a warning, a mute or a ban, depending on how serious it is. To contest a decision, write through the Contact page.

Deleting your account

  • Your scores are removed from the rankings immediately.
  • Your data is permanently deleted at the end of the month. Until then you can restore everything by logging in again.

Availability and liability

  • No guarantee of availability: a service can be interrupted, changed or stopped.
  • To the extent the law allows, the author is not liable for losses linked to the use of the site, the online services or test builds. Nothing here excludes a liability that the law does not allow to be excluded, nor removes your mandatory consumer rights.
  • These terms do not choose any particular governing law.

Changes and contact

  • These terms may change: the update date is at the top of this page. For any question, see the Contact page.

Credits

Prism is not affiliated with any of the projects below; their names belong to their authors.

  • osu! — osu! and osu!mania are the work of ppy and the osu! community. Indexed maps come from the official API (v2) and link back to osu.ppy.sh; their creators are credited.
  • Etterna and StepMania — Indexed packs are the EtternaOnline packs. Thanks to the Etterna team and the StepMania community (.sm and .ssc formats).
  • Quaver — Quaver and its difficulty model, reimplemented in Metron.
  • MinaCalc and Metron — Etterna difficulty comes from MinaCalc (the Etterna team). Metron gathers MinaCalc, Quaver, osu!mania, Interlude and in-house calculators in one MIT-licensed Rust library.
  • ROX (Rhythm Open Exchange) — The chart exchange format used by the game and by the index, MIT licence, copyright 2024 Osef.
  • Other libraries — rosu-replay (osu! replay reader, MIT), Rust, Loco, SeaORM, BLAKE3, Svelte and SvelteKit, PostgreSQL, Caddy, each under its own free licence.
  • Font — JetBrains Mono NL, SIL Open Font License 1.1: license text.

Licence

The game's code declares the GNU Affero General Public License, version 3 only (AGPL-3.0-only). The full licence text and the public address of the source code are being published: this page will point to them as soon as they are online. Third-party components keep their own licences, cited above.

Removal request

Map creator, rights holder or plain visitor: to have a map, a creator or a pack removed from the index, or a credit corrected, write through the Contact page with the address of the entry concerned. A well-founded request is handled without delay: the entry disappears from the index and its chart data is deleted from the server.