Quick Start

Lightweight SQLite WAL sync to S3 in Rust.

Why Walrust?

Walrust is built for curiosity, efficiency, and Rust-native integration.

Curiosity

I built walrust because I was interested in it, and because I was doing silly things with millions of databases on a single server. Think a SaaS platform where every customer gets their own SQLite database - I needed the lowest memory overhead possible and the fastest sync possible (see redlite).

Memory Efficiency

Walrust’s Rust implementation has a smaller memory footprint:

Measured overhead:

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

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

Rust-Native

Walrust integrates naturally into Rust projects:

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

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Installation

CLI (Rust)

cargo install walrust

Python

pip install walrust

Verify

walrust --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:

walrust 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:

walrust 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:

walrust 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:

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

Create a Read Replica

Run a local read replica that polls S3 for changes:

walrust 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 Walrust? - Multi-tenant SQLite use case
• CLI Reference - Full command documentation (including replicate)
• Configuration - Environment variables and options
• Deployment - systemd, Docker, Kubernetes guides