Sync without the middleman.
Your devices find each other automatically and stay in sync — no cloud required. Share with other PrivStack users too, not just your own devices.
Built on libp2p with QUIC transport. Your devices discover each other via mDNS (local) or Kademlia DHT (global), authenticate with the Noise protocol, and sync bidirectionally using CRDTs. Share with other PrivStack users too — not just your own devices.
Direct device-to-device sync
PrivStack syncs your devices directly — no cloud server in the middle. Pair with a simple 4-word code (like "PEAR-MANGO-KIWI-GRAPE"), approve each device, and share specific documents with the people you choose. Everything is encrypted end-to-end.
PrivStack uses peer-to-peer sync powered by libp2p. Your devices connect directly via QUIC, encrypting everything end-to-end. Pair with easy 4-word sync codes (e.g., "PEAR-MANGO-KIWI-GRAPE"), approve trusted peers manually, and share specific documents with granular per-entity permissions. Even relays see only encrypted packets.
The middleman problem
Traditional sync requires a server in the middle — a single point of failure, a target for hackers, a place where your data sits vulnerable. And sharing files or documents with others usually means uploading to a third-party cloud.
What You Get
- libp2p networking with QUIC transport (UDP, low-latency)
- mDNS discovery on local networks (zero configuration)
- Kademlia DHT for global peer discovery (opt-in with sync code)
- 4-word sync codes for easy, private pairing
- Manual peer approval before trust is established
- CRDT-based conflict resolution (mathematically guaranteed convergence)
- Bidirectional delta sync — only missing events exchanged
- Share specific entities with other PrivStack users
- Per-entity access control (Viewer / Editor / Admin / Owner)
- Relay fallback for NAT/firewall traversal (E2E encrypted)
- Vector clocks for causal ordering across peers
- Event batching for network efficiency (configurable batch size)
- Fast, low-latency connections between your devices
- Automatic discovery on your home or office network
- Works across the internet, not just your local network
- Pair devices with a simple 4-word code
- You approve each device before it can sync
- Edits from all devices merge automatically — no conflicts
- Only new changes are sent — efficient and fast
- Share specific notes, tasks, or files with others
- Control who can view, edit, or manage your shared items
- Works even behind firewalls — encrypted relay as backup
- Changes stay in the right order across all devices
- Changes sync efficiently in the background
Ready to get started?
Try PrivStack free for 7 days. Your data stays on your devices.