Quick Start

Lightweight SQLite WAL sync to S3 in Rust.

Why Walsync?

Walsync is built for control, efficiency, and Rust-native integration.

Control

You own the code. No black box, no surprises. If you need a custom feature or fix, you can implement it. Walsync is designed to be hackable and transparent.

Memory Efficiency

Walsync’s Rust implementation has a smaller memory footprint:

Measured overhead:

• walsync: ~12 MB baseline
• Litestream: ~33 MB baseline

For resource-constrained environments (small VMs, containers, edge deployments), this difference matters.

Rust-Native

Walsync integrates naturally into Rust projects:

• Native async/await with tokio
• No CGO dependencies
• Smaller binary size (~8 MB)
• LTX format compatible with Litestream

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Installation

CLI (Rust)

cargo install walsync

Python

pip install walsync

Verify

walsync --version

Set Up Credentials

Configure your S3 credentials. Example for Tigris (Fly.io):

export AWS_ACCESS_KEY_ID=tid_xxxxx
export AWS_SECRET_ACCESS_KEY=tsec_xxxxx
export AWS_ENDPOINT_URL_S3=https://fly.storage.tigris.dev

See S3 Providers for AWS, R2, MinIO, and other providers.

Take a Snapshot

Back up your database to S3:

walsync snapshot myapp.db --bucket my-backups

Output:

Snapshotting myapp.db to s3://my-backups/myapp.db/...
✓ Snapshot complete (1.2 MB, 445ms)
  Checksum: a3f2b9c8d4e5f6a7...

Watch for Changes

Continuously sync WAL changes:

walsync watch myapp.db --bucket my-backups

This watches for database changes and syncs them to S3. Run this as a background service in production.

Restore

Restore a database from backup:

walsync restore myapp.db --bucket my-backups -o restored.db

Output:

Restoring myapp.db from s3://my-backups/...
  Downloading snapshot... done (1.2 MB)
  Verifying checksum... ✓
✓ Restored to restored.db

Watch Multiple Databases

Sync multiple databases with a single process:

walsync watch app.db users.db analytics.db --bucket my-backups

Create a Read Replica

Run a local read replica that polls S3 for changes:

walsync replicate s3://my-backups/myapp.db --local replica.db --interval 5s

Output:

Replicating s3://my-backups/myapp.db -> replica.db
Poll interval: 5s
Press Ctrl+C to stop

Bootstrapped from snapshot: 1024 pages, TXID 100
[10:30:05] Applied 1 LTX file(s), now at TXID 101

The replica auto-bootstraps from the latest snapshot if it doesn’t exist, then applies incremental updates.

Next Steps

• Why Not Litestream? - Detailed comparison
• CLI Reference - Full command documentation (including replicate)
• Configuration - Environment variables and options
• Deployment - systemd, Docker, Kubernetes guides