DeltaSync

⚠ REQUIRES YOUR OWN SERVER. DeltaSync does nothing on its own. You must first install and run the self-hosted DeltaSync server (PHP + PostgreSQL), or have access to someone else's, and enrol this device against it. There is no public or default server — without one, this app has nothing to sync and cannot even be set up. If you just want a standalone KeePass app, this is not it: use KeePass2Android or KeePassDX instead.

DeltaSync keeps a KeePass (.kdbx) database synchronised across your devices through a server that only ever sees encrypted blobs. Your master password never leaves the device, and the server cannot read entry titles, usernames, passwords, notes or attachments — even if it is compromised.

How it differs from other KeePass sync solutions:

• Entry-level deltas: only changed entries cross the wire, not the whole .kdbx file. Fewer bytes uploaded, fewer wholesale conflicts.

• Real end-to-end encryption: per-entry XChaCha20-Poly1305 with a key derived from your master password via Argon2id and HKDF-SHA256. The server stores opaque ciphertext.

• Concurrent edits merge: two devices editing different entries merge cleanly. If both change the same entry, the most recent edit wins.

• Multi-user sharing without key escrow: NaCl sealed-box wraps the database master key to each recipient's device public key. The server sees who has access, not what they can decrypt.

• Open source from end to end: the AGPL-3.0 server (PHP/PostgreSQL), GPL-3.0 desktop client (Go), and this GPL-3.0 Android client are all published. You can self-host the server, or use someone else's.

This app pairs with KeePass2Android or KeePassDX as your editor — DeltaSync itself is a background sync service and does not display your passwords. You point it at a .kdbx file on the device, supply the master password once, and it keeps the file in sync with the server through WorkManager.

Project: https://gitlab.com/Star95/keepass-deltasync
Website: https://deltasync.org

Groups sync too: group structure and which group each entry belongs to stay in sync across devices, alongside the entry contents.

Status: v0.4 — the sync layer (entries + groups) is feature-complete and tested; the UI is functional but still minimal. Treat as beta.

Recent changes:
DeltaSync now targets Android 16 (API 36), the level Google Play requires for new apps, and its native code is aligned for phones that use 16 KB memory pages. Nothing changes in how the app works.