Walnut Chess

Privacy

Privacy policy

Last updated 10 October 2026. This page says what Walnut Chess (walnutchess.com) keeps about you, why, and who else sees it. We keep what the app needs to coach you, and nothing is sold.

What we keep

  • Your account. Your email address, display name, username and, if you set one, a password (stored only as a one-way hash).
  • Sign in with Google. If you continue with Google, Google tells us your name, email address, profile picture and an ID for your Google account. We use them to make or find your account and to sign you in. We don't get your Google password or anything else in your Google account.
  • Your chess. Games, puzzles, lessons, training cards, ratings, the plan the coach made with you, your chats with the coach, games you import, and feedback you send us with any files you attach.
  • Your devices. Your time zone, language, the kind of device and browser you use, your approximate location (country, region and city, from your connection) and when you use the app. This keeps your streak on your own days, shows the app in a layout that suits you, and helps us see how it's used.

Who else sees it

  • Anthropic writes the coach's words. What you ask the coach, the position on the board and what the coach knows about your chess go to Anthropic's API to write each reply. Anthropic doesn't use it to train its models.
  • Resend sends our emails, so it sees your email address and the email.
  • Cloudflare carries traffic to the site.
  • Google, only if you sign in with Google.
  • Your friends see your name and username, and your ratings and progress if you share them (you can turn that off in Settings).

We don't sell your data or show ads. The public pages of walnutchess.com (this one, the blog and the like) use Google Analytics to count visits. The app itself uses no analytics or advertising cookies: the one cookie it sets keeps you signed in.

How long we keep it, and deleting it

We keep your data while you have an account. You can delete your account in the app under Settings, Delete account; that removes your account and everything in it. Some records stay briefly in backups before they're overwritten, and we keep a short note that an account was deleted.

Children and kids mode

Children under 13 shouldn't make an account of their own. A child of 5 to 12 can play on a kids account that a parent or guardian sets up and looks after:

  • A grown-up sets it up. The parent or guardian signs up with their own email address and, in the first chat with the coach, says a child will play and confirms they are the child's parent or guardian. We keep a record of that confirmation.
  • Nothing extra about the child. We keep the same chess data as for any account: games, puzzles, lessons, flashcards and chats with the coach. We don't ask for the child's age, school, photo or where they live.
  • The coach. What the child types to the coach goes to Anthropic to write the reply, as for every player, and isn't used to train its models. On a kids account the coach is told to keep to chess, never to ask for personal details, and to send the child to a trusted grown-up if something sounds worrying.
  • Other players. Kids accounts can't be found in friend search or asked to be friends by username, and there's no chat between players. A child can only add a friend through an invite link.
  • In the app, there are no ads and no analytics or advertising trackers.
  • The grown-up stays in charge. Switching kids mode off needs the account password. If we send the weekly note on what the child played, it goes to the account's email address and can be turned off in Settings. The account and everything in it can be deleted from Settings at any time.

If you think a child has an account without a parent or guardian, or you'd like us to delete a child's data, email [email protected] and we'll delete it.

Questions

Email [email protected], or, signed in, use Help & feedback in the app. We'll update this page if any of this changes.