Now in development for Windows

Your files.
Your network.
Your rules.

Peer-to-peer file sync with zero central storage. No corporation holds your data. Your backup payments go to real people, not big tech.

Grass Drive Sync Engine
grassdrive sync --status
  Peers online: 3 of 3
  Files synced: 2,847 files (42.6 GB)
  Backup shards: 16/16 healthy
  Encryption: AES-256-GCM + mTLS active
  Earnings: $12.47 this month
  ───────────────────────────
grassdrive detect report.pdf changed
  SHA-256 computed → manifest exchanged
  Syncing to 2 peers... done (340ms)

Built with proven technologies

AES-256-GCM Ed25519 .NET 8 gRPC + mTLS Reed-Solomon SQLCipher

Everything you need.
Nothing you don't.

File sync that works how you expect, built on infrastructure you can trust.

Peer-to-Peer Sync

Files transfer directly between your devices over encrypted gRPC connections. No cloud middleman stores or routes your data.

Explorer Integration

Grass Drive appears in your Windows Explorer sidebar via Cloud Files API. Sync status overlays, drag-and-drop — just like OneDrive, but yours.

Folder Sharing

Right-click any folder to share with contacts. Invitation by email, manage active, pending, and sent shares from the app.

Version History

Every version of every file is kept for 30 days. Made a mistake? Restore any previous version with one click.

Soft Delete & Trash

Deleted files go to a 30-day trash. Recover accidentally deleted files or let them expire automatically.

Conflict Detection

Version vectors detect concurrent edits across peers. Both copies are kept with clear naming so you never lose work.

Selective Sync

Choose which folders sync to which devices. Changes made offline queue up and sync automatically when you reconnect.

Large File Support

Chunked transfers with automatic resume. Connection drops mid-transfer? It picks up exactly where it left off.

Security isn't a feature.
It's the foundation.

Military-grade encryption at every layer. Your files are protected at rest, in transit, and in backup — by design, not by policy.

Ed25519 Peer Identity DPAPI

Each device gets a unique Ed25519 key pair. Peer ID is derived from SHA-256 of the public key — cryptographically verifiable, unforgeable.

Mutual TLS on Every Connection mTLS

Every peer-to-peer connection is authenticated in both directions. No man-in-the-middle attacks. Both sides prove identity before any data flows.

AES-256-GCM Backup Encryption Zero-Knowledge

Backup shards are encrypted before leaving your device. Backup peers store ciphertext they cannot decrypt. Even we can't read your files.

Encrypted Local Database SQLCipher

All local metadata is stored in SQLite encrypted with SQLCipher. Even if someone accesses your disk, your sync state is unreadable.

Email-Based MFA

Multi-factor authentication on every login and new device registration. 6-digit code via email with 10-minute expiry.

No Central File Storage

Your files never touch a corporate server. The coordinator matches peers and issues tokens — it never sees, stores, or routes your actual data. When you pay for backup, that money goes to real people contributing storage, not big tech.

From file change to
distributed backup

Your file is detected, hashed, synced, compressed, encrypted, erasure-coded, and distributed — in seconds.

01

Change Detected

FSWatcher monitors your Grass Drive folder in real time. The moment a file is saved, renamed, or deleted, the sync engine wakes up. A 1-2 second debounce coalesces rapid saves into a single event.

02

Hash & Manifest Exchange

A SHA-256 hash is computed for the changed file. Your device exchanges manifests with connected peers — a compact list of file paths, hashes, and version vectors — to determine what needs syncing.

03

Peer-to-Peer Transfer

Changed files stream directly to your other devices over gRPC with mutual TLS. Large files are chunked with automatic resume. Bandwidth throttling keeps your connection usable.

04

Compress & Encrypt

For backup, the file is compressed with zstd (60-80% reduction for text) then encrypted with AES-256-GCM using a per-file key derived from your master key. Compression before encryption — because ciphertext is incompressible.

05

Erasure Code & Distribute

Reed-Solomon 8+8 splits the encrypted file into 16 shards — 8 data, 8 parity. Each shard goes to a different backup peer. Any 8 of 16 shards can reconstruct the original. When a node goes offline, the network automatically replicates its shards to new peers — maintaining full redundancy at all times.

Recovery: Any Device, Any Time

Lost your laptop? Log in on a new device, authenticate with MFA, and Grass Drive gathers 8+ shards from the network. Reconstruct decrypt decompress your original files, restored.

Watch your data flow.

A file is saved, hashed, synced to peers, encrypted, sharded, and distributed — all in real time.

File data Encrypted Shards Sync signal

Turn spare disk space
into income.

Contribute storage to the Grass Drive network as a backup peer. Store encrypted shards you can never read, earn money for keeping them safe. Every dollar goes to people like you — not a corporation.

$3.20
Avg. monthly per 1TB contributed
98.2%
Network uptime target
Earnings proportional to uptime and storage contributed
Zero-knowledge — you store ciphertext, never see file contents
Automatic shard rebalancing keeps the network healthy
Stripe Connect payouts directly to your bank account
Track earnings, uptime stats, and payout history in-app
Reed-Solomon 8+8 Erasure Coding
D1
D2
D3
D4
D5
D6
D7
D8
P1
P2
P3
P4
P5
P6
P7
P8
Data shards (8)
Parity shards (8)
Peers offline (3)
13 of 16 shards available — only 8 needed to reconstruct. Multiple redundant copies across different peers means your files survive even when half the network goes offline. Automatic repair kicks in if any nodes go offline.

Simple, fair pricing.

Contribute to the network and sync for free. Or pay a flat monthly rate — and every cent goes to the people storing your data, not a tech giant.

Paid
$1.99/mo
per 100GB backed up
All the sync and backup features without contributing disk space. Your payment goes directly to the people storing your encrypted data — not a corporate cloud.
  • Everything in Community
  • No storage contribution required
  • Priority shard placement
  • Stripe billing & invoices
Start Free Trial

Take back your files.

Download Grass Drive for Windows and join a network where your data belongs to you — and your money goes to people, not big tech.