Privacy

What MyBookCat stores

Your account, username, full name, email address and a hashed PIN, used to sign you in and to show who's who in a shared library.

Your catalogue, the books you add (titles, authors, ISBNs, tags, shelf locations, loans, wishlist, reading progress) and the cover photos you upload. This is your data; the app exists to keep it for you.

Usage statistics, anonymous-by-design counters (books added, scans attempted, whether an AI result needed correcting). We never store what you searched for, the text of your notes in analytics, or your location.

Where it goes

Data lives in our database and file storage (hosted by Supabase) and the app is served by Vercel. When you photograph a book so the app can read its cover, that photo is sent to an AI provider for the extraction and is not used to train models. Today that provider is Anthropic. For books with no readable barcode we may also route the photograph to another vision model through OpenRouter, which is the only case where a photo reaches a provider other than Anthropic; scanning a barcode and looking up an ISBN never send a photograph anywhere. ISBN lookups query Google Books and Open Library with the ISBN only. We don't sell data or use advertising or tracking SDKs.

Sharing you control

Libraries are private until you invite someone or turn on a public link. The public page shows only the fields you tick, and switching it off removes access immediately.

Deleting your data

Settings → Delete account permanently removes your account, the libraries you own and their cover photos. Usage statistics are kept in anonymized form with no link to you. See Support for help.