Sync your vault.
Keep it private.
Secure-Smart-Sync is an Obsidian plugin that syncs your vault to Cloudflare R2 with client-side encryption. Your files are encrypted before they ever leave your device — no exceptions.
Everything you need to sync privately
Built around a single principle: your notes never touch a server in plaintext.
Client-Side Encryption
Files are encrypted on your device using AES-256-CBC before upload. The remote never sees plaintext — ever.
Smart Sync
Syncs silently after you stop writing. Other open devices are notified instantly via a relay — no polling delay.
Cloudflare R2 Storage
Uses Cloudflare R2 — S3-compatible, zero egress fees, generous free tier. You own the bucket. No vendor lock-in.
3-Way Sync Engine
Compares local, remote, and last-known state to make correct decisions — even after offline editing on multiple devices.
Easy Device Pairing
Share credentials to a new device in seconds using a one-time pairing code — no manual copy-pasting of keys.
Desktop & Mobile
Works on all platforms Obsidian supports. A dedicated floating indicator on mobile keeps sync visible without interruption.
How it works
From keystroke to synced — the full picture.
You write in Obsidian
The plugin watches for changes. Smart Sync starts a short idle timer each time you type.
Files are encrypted locally
Before any file leaves your device, it is encrypted with your password using AES-256-CBC. Filenames are also encrypted via Salsa20.
Uploaded to your R2 bucket
Encrypted blobs are pushed to your Cloudflare R2 bucket. Only changed files are transferred — not the full vault.
Other devices are notified
A lightweight sentinel signal is written to R2. Other open devices detect it within seconds and begin pulling changes.
Decrypted on arrival
Downloaded files are decrypted on the receiving device using your password — never on any server.
Zero egress fees. Generous free tier. You own the bucket.
Cloudflare R2 charges $0 for data egress — the fundamental flaw of traditional cloud storage for sync tools. Most users will never pay anything.
- 10 GB free object storage per month
- 1 million Class A operations per month
- 10 million Class B operations per month
- Unlimited free egress bandwidth
Ready to get started?
Browse the full documentation — from quick setup to advanced architecture. Estimate your Cloudflare usage with the token calculator.
Sync reliably. Keep a backup.
Secure-Smart-Sync has been tested across multiple devices and typical workflows. As with any sync system, edge cases can occur in complex scenarios — offline conflicts, unusual file structures, or interrupted syncs. Keeping a local backup of your vault is always a smart habit.
Issues? Open a GitHub issue — every report genuinely helps.