Privacy policy

Last updated: October 16, 2026

Data controller

Jertho SRL, [TODO registered office address]. Contact: [TODO contact email].

This website

This website sets no cookie and uses no analytics nor advertising tool. It is hosted by Cloudflare, which processes the ip address of the visitors to deliver the pages and protect the website against abuse.

The app: what we keep

KikouBook asks for no name, email, phone number nor password. We keep:

• for each device: the fingerprint of its secret key (the key itself stays in the browser), a name derived from the browser (e.g. "Safari on iPhone"), or the one you give it in the settings, shown on your own devices only, its creation and last use dates;
• the fingerprint of your recovery code, if you created one;
• your libraries, their books, series, ratings and comments;
• in a library shared with you: the nickname you use there, your reservations and book suggestions.

The ip address is used to limit abuse (number of requests) and may appear in the technical logs of the server, kept [TODO duration].

To look up a book, our server queries the Bibliothèque nationale de France and Open Library with the searched text or the ISBN, without any information about you.

The covers of the books of your libraries are downloaded once and for all by our server, which then sends them to you itself. The covers of the search results, and the ones our server has not downloaded yet, are loaded directly by your browser from Open Library (archive.org), the Bibliothèque nationale de France or Google Books, which then receive your ip address, as for any image shown on a web page.

What your relatives see

The relatives you share a library with see its books, their statuses and its series, and know that a book is reserved, without knowing by whom. They never see your ratings nor your comments. You see their nickname and who reserved which book.

Browser storage

The secret key of the device is kept in the local storage of the browser: it is required to find your libraries and is never used for tracking. When you create a share link, its code is kept there too, to show it again on this device as long as it is valid (our server only keeps its fingerprint).

Your preferences are kept there too: the language of the app (on the first start, the one of your browser when it is available), the light or dark theme, the display of the books as a list or a grid, the last library and status chosen to add a book, and the date when you hid the storage warning. They stay on your device.

So that you can read the app without network, this storage also holds a copy of what the app shows you: your libraries with their books, series, notes and comments, the reservations and nicknames of your relatives, the recent activity, and the libraries shared with you (without the notes nor the comments of their owner), with the covers of their books. This copy stays on your device and is sent to no one. It is erased when the device is linked to other data (pairing or recovery code), when you start again from scratch, or when the device is removed from another device; you can also erase it by deleting the data of the site in your browser.

Legal bases

The data of the app is processed to provide the service you use (article 6.1.b GDPR); the ip address, for the security of the service (legitimate interest, article 6.1.f).

Hosting and retention

The data of the app is hosted by [TODO VPS hosting provider, address], and its backups by Cloudflare (R2) [TODO region]. It is kept as long as you use the service, until it is deleted [TODO retention of inactive devices].

Your rights

You can delete your libraries and remove your devices yourself in the app, or delete all your data from its settings ("Delete my data"): your libraries with their books, series, ratings and comments, your relatives' access, your access to the libraries shared with you and your reservations, your devices and your recovery code are erased 30 days after your request. Until then, nothing changes and you can cancel from any of your devices. The books of the catalog, shared by everyone, are kept. Erased data remains in the backups until they expire [TODO backup retention]. You have the right to access, rectify, erase, restrict, object and port your data: write to us at [TODO contact email].

You can lodge a complaint with the Belgian Data Protection Authority, rue de la Presse 35, 1000 Brussels (dataprotectionauthority.be).