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.