Privacy policy

Last updated 5 October 2026.

Who we are

NRV Chess (“we”) is run by Nathan Vucovich, who operates nrvchess.com and the NRV Chess iOS app and is responsible for the personal data described here. Contact us about anything on this page at support@nrvchess.com.

What we collect today

NRV Chess is in preview, and free. You need an account to play.

• Your account. Your email address and an account ID. Your password is stored only as a one-way hash by our sign-in provider; we can't see it. We use your email to confirm your account, reset your password and, rarely, tell you about important changes to the service.
• Your sign-in. A sign-in token keeps you signed in. It is kept in a cookie in your browser, or in your phone's keychain, and our engine checks it so that it only answers signed-in players and so we can limit abuse.
• Your games. Each move is sent to our engine so NRV Coach, our chess engine opponent, can reply and judge it. We save your games to your account: the side you played and NRV Coach's settings, every move you and NRV Coach played with the engine's assessment of it, and each mistake the coach stopped you on with what it showed you. Only the first try at a move is kept, so retrying a mistake doesn't erase it. We use them to build your accuracy and mistake history. For openings, the engine looks the position up in the lichess opening explorer; that request carries only the chess position, never your account.
• Coaching explanations. When the coach stops you on a mistake, we add our engine's analysis of it to the saved mistake (the better move, the lines that follow, and how often players chose each move in public lichess games). We send that position and analysis to Anthropic, which runs the Claude AI model, to write the explanation the coach shows you, and we keep the explanation with the mistake. We send Anthropic only the chess position and analysis: no name, email address, account ID or other details about you. Anthropic may use this chess data to train and improve its AI models.
• Your Lichess account, if you link it to import games. When you choose Link Lichess account, you sign in on lichess.org itself (we never see your Lichess password) and Lichess tells us your account's username and ID. We store those, when you linked, the progress of your imports, and an access token Lichess gives us. We ask Lichess for no permissions beyond knowing who you are; the token only lets us download your games faster. It is kept encrypted in our database's secrets vault, is never shown to you, to other players or in our logs, and is revoked at Lichess when you unlink, when you delete your account, or when another NRV Chess account later signs in with the same Lichess account (that newer link takes over, and we tell you).
• Your Chess.com and Lichess usernames, if you link them for ratings. When you link an account in your profile so NRV Coach can start at your level, we save its username to your account, with the bullet, blitz and rapid ratings last read from that site and when they were read, so the link follows you when you sign out or use another device. Your browser or phone reads those ratings directly from the site's public profile, so Chess.com or Lichess sees that request. Anyone can look up these ratings, so linking doesn't prove the account is yours, and we use them only to pick NRV Coach's starting strength. Unlinking deletes the username and ratings from your account.
• Imported games. With a linked Lichess account we fetch your 100 most recent games, then new ones about every hour: the moves, date, result and how the game ended, the time control, how long each move took on the clock for the first 20 moves (yours and your opponent's), the opening, your rating and Lichess's own analysis where Lichess has it, and your opponent's Lichess username and rating. Your opponents' names and ratings are other players' personal data. They are already public on Lichess, and we keep only these two, to show who you played, under our legitimate interest in showing you your own games. Lichess offers no chat in these downloads and we keep no comments. Our engine analyzes the first 20 moves of each game and saves its assessment of your moves and your mistakes, which feed your accuracy history, the opening tree and “Find my opening leaks”. An imported mistake goes to Anthropic only if you ask the coach to explain it, as described below.
• Technical logs. Like any website, our hosting providers record IP addresses, browser type and request times in server logs, which we use for security and fixing faults.
• Website visits. On nrvchess.com we count visits with Vercel Web Analytics: the page, the referring site, and your country, device type, browser and operating system. It uses no cookies and doesn't store your IP address; a visitor is recognized only within one day, through a hash that is discarded. We use these totals to see which pages and links bring people in. The iOS app doesn't use it.

What stays on your device

Your display name, icon, profile photo and game settings are stored only in your browser or on your phone. Signing out, clearing your browser's site data or deleting the app removes them. The usernames you link for ratings are no longer among them: they are saved to your account, as described above. If you linked one on a device before we started saving them, the app uploads it to your account the next time you sign in there and removes the copy on the device.

Linking Lichess to import your games is separate from linking it for ratings: you prove the account is yours by signing in on lichess.org, and that link, its token and your imported games are kept on our servers as described above.

How we use it, and our legal basis

Only to run the service you asked for (playing against NRV Coach and getting coached) and to keep it secure. Where data protection law asks for a legal basis, it is performing our service for you and our legitimate interest in preventing abuse. We do not sell or share your personal information, we show no ads, and we do not track you across other sites or apps.

Cookies

We use only what the service needs to work: the sign-in cookie above and the security check described below. We use no analytics, advertising or tracking cookies, so there is nothing to opt into.

Service providers

These companies process data on our behalf, under contracts that limit them to doing so:

• Supabase (accounts, sign-in and database)
• Resend (sending account emails, such as confirmation and password reset links)
• Google Cloud (chess engine analysis)
• Anthropic (writing coaching explanations of your mistakes with its Claude AI model, from the position and our engine's analysis; Anthropic may use what we send it to improve its models, which is why we send it only the chess position and analysis and nothing about you)
• Vercel (website hosting and cookieless visit counts)
• Cloudflare (our domain's DNS, and Turnstile, which checks that a person rather than an automated script is signing up or signing in; most people never see it). Turnstile is subject to Cloudflare's privacy policy.

Lichess is not one of our providers: it is where your imported games come from. When you link it and while it stays linked, our servers request your games from lichess.org (with your token, or our own), so Lichess sees those requests, under its own privacy policy.

Our providers are based in the United States, so your data is processed there. Where the law of your country requires it, transfers rely on the providers' standard contractual clauses or the EU-US Data Privacy Framework.

How long we keep it

Your account, and the games, moves, mistakes, explanations and ratings links saved to it, are kept until you delete your account; deleting it deletes them too. A ratings link is also deleted when you unlink it. Imported Lichess games and their analysis are kept until you unlink Lichess or delete your account: unlinking deletes the link, its token (revoked at Lichess) and every imported game together. You can also delete a single imported game from My games. If another NRV Chess account later links the same Lichess account, we stop importing to yours, revoke your token and keep the games already imported until you unlink or delete them. The chess positions themselves also go into a shared table of positions and engine analysis that holds nothing about who played them, and that stays. Server logs are deleted by our providers on their standard schedules, usually within 30 days. Anthropic keeps the chess positions and analysis we send it under its own retention policy and may use them to improve its models; they contain nothing that identifies you.

Deleting your data

Open your profile and choose Delete my account, on the website or in the app. That deletes your account and everything tied to it on our servers, including your saved games, moves, mistakes and explanations, the usernames and ratings you linked, your Lichess link and imported games (and revokes the Lichess token), signs you out, and clears your profile and settings from that browser or phone. To remove only the Lichess data, choose Unlink Lichess in your profile.

Your rights

Depending on where you live (for example under the GDPR, the UK GDPR or US state privacy laws) you can ask to access, correct, delete or receive a copy of your personal data, object to or restrict how we use it, and withdraw consent. Email support@nrvchess.com; we answer within 30 days and won't treat you differently for asking. You can also complain to your local data protection authority.

Children

NRV Chess is not directed to children under 13, and we do not knowingly collect personal information from them. If you believe a child under 13 has given us personal information, email us and we will delete it.

Do Not Track and Global Privacy Control

We don't track you across sites, so there is nothing for a Do Not Track or Global Privacy Control signal to turn off. We never sell or share personal information either way.

Changes

When the service changes what it collects or who processes it, we will update this page and the date above before the change goes live, and tell you in the app if the change is significant.

Contact

support@nrvchess.com