Your book is not a performance.

The Book Between Us is designed for exactly two writers. It has no public profiles, audience, feed, likes, relationship scores, or advertising inside private books.

What the beta stores

To identify each writer, the beta receives a stable account identifier and verified email address from its private entry service. Passkeys remain protected by your device and are never received or stored by The Book Between Us. The app stores the names you choose inside the book, distance dates, weekly opening rhythm, same-city confirmations, chapters, drafts, closed pages, plans, invitations, sealed letters, Little Box ideas and results, literary cabinet entries, parallel memories, and media-delivery records.

Who can read the writing

Book data is checked against membership on the server. A private draft is returned only to its author. The other writer receives its status, not its contents. Both answers are returned to both members only after both pages are closed.

Sealed reunion letters

After a letter is sealed, its text is not returned to the app before the reunion date. A date lock cannot prove that no database operator could ever access stored data, so the beta does not describe sealed letters as end-to-end encrypted.

Encrypted envelopes

Postbox notes, letters, photographs, and photograph captions are encrypted with AES-GCM on the sender’s device before upload. Photographs are also resized and converted to WebP to remove camera and location metadata. The shared envelope key travels in the private fragment of the invitation link, which browsers do not send to the server, and is then kept in each device’s private browser database. The service stores encrypted contents and delivery metadata such as sender, recipient, time, kind, and file size, but it does not receive the key.

If both writers lose every copy of their envelope key, encrypted Postbox contents cannot be recovered. A writer can copy the key from a paired device through Our book to pair another device. Treat that key like a private letter and share it only with the other writer.

Gift secrets and chapter artifacts

A private gift idea is returned only to the person who created it. A partner may draw only an intentionally offered wish clue; secret titles and secret-drawer activity are excluded from their responses and exports. Chapter photographs and voice readings use the same device-held encryption key as photograph envelopes. Captions, dates, places, ownership, and storage size remain protected server data visible only to the book’s two members.

Control and deletion

Either writer can download the book data currently available to them. The creator can permanently delete the entire book. The invited writer can permanently remove their own membership and contributions.

Beta limitation

Email verification, sessions, and passkey public keys are stored in the app’s own private database. A specialist email carrier processes only the address and short-lived entry code needed to deliver your sign-in letter. The carrier does not receive your book, letters, photographs, or encryption keys. Do not use the beta for information that would put either person at risk if disclosed.