Nothing. Kamui does not collect, transmit, sell or share any personal data. There is no sign-up, no user account, no advertising and no usage tracking or telemetry. The app works fully offline.
Everything you enter is stored only on your device, inside a vault file
(.kamui). Each vault is encrypted with a key derived from your passphrase
using Argon2id, and sealed with authenticated XChaCha20-Poly1305
encryption (libsodium). Without your passphrase, the contents cannot be read — not by
us, and not by anyone who obtains the file.
So a locked vault can be identified and shown before you unlock it, a small amount of metadata is stored in the file in plain text. This is by design, and is no more than a file on disk already reveals:
Your actual entries — passwords, numbers, notes and every field value — are always inside the encrypted portion.
If you enable fingerprint/face unlock, your passphrase is stored locally on that device, encrypted by the operating system's keystore and released only after a successful biometric check. It never leaves the device and never travels with a vault file you share. You can turn it off at any time, which forgets the stored copy.
When you share or back up a vault, you share the encrypted file; the recipient still needs the passphrase. If you choose the explicit "export as plaintext" option, that file is unencrypted by your request — handle it carefully.
Kamui makes no network connections for its core function. It does not request access to your contacts, location or other personal data. On mobile, system features you invoke — a file picker, the share sheet, the biometric prompt — are handled by your operating system.
Kamui is a general-purpose tool and does not knowingly collect data from anyone of any age, because it collects no data at all.
Because Kamui collects nothing, this policy rarely changes. Any update will be reflected by the date above.