No sign-up, no server that knows who you are. Tally Stick is built on four simple ideas — a phrase, a keystore, a key per shared group, and a server that never sees any of it.

1. 1

   One recovery phrase

   On first use, Tally Stick generates a 24-word recovery phrase. Those words are your identity — there's no account, username, or password behind them.

2. 2

   The phrase unlocks your keystore

   The phrase derives a master key that encrypts a small personal keystore — the list of shared spaces you belong to and the key for each.

3. 3

   Each shared space has its own key

   An expense group has one group key. Everything in it is stored as documents encrypted with that key. Sharing the space means sharing that one key — via a QR code or invite — and the space's owners decide who's in. Remove someone and the key is rotated and re-shared to everyone who remains, so they see nothing new.

4. 4

   A blind server just relays ciphertext

   Your devices sync through a server that stores and forwards encrypted blobs and pushes live updates. It never holds a key, so it cannot read anything it syncs.

Adding a device or sharing: scan a setup QR from a device you already have, or enter the 24 words — the new device pulls your keystore and you're in. Live sync self-heals: if a device goes offline it catches up on reconnect, so every device ends up showing the same thing.