---
name: litestream
description: SQLite disaster recovery and streaming replication to cloud storage (S3, GCS, Azure, SFTP, NATS). Use this skill for configuring Litestream, deploying to cloud platforms, troubleshooting WAL replication issues, implementing point-in-time recovery, and setting up VFS read replicas.
version: 0.5.5
---

# Litestream

Litestream is a disaster recovery tool for SQLite that runs as a background process, continuously replicating database changes to cloud storage. It monitors the SQLite Write-Ahead Log (WAL), converts changes to immutable LTX files, and uploads them to your chosen storage backend.

## Key Concepts

- **WAL Monitoring**: Watches SQLite Write-Ahead Log for changes at configurable intervals (default 1s)
- **LTX Files**: Immutable files containing database page changes, never modified after creation
- **Level-Based Compaction**: Multi-level system (L0-L9) that merges LTX files to reduce storage overhead
- **Point-in-Time Recovery**: Restore to any transaction using TXID or timestamp
- **VFS Support**: Read replicas directly from cloud storage without local database copy
- **MCP Server**: AI tool integration for automated database management

## Quick Start

### Installation

```bash
# macOS
brew install litestream

# Linux (Debian/Ubuntu)
wget https://github.com/benbjohnson/litestream/releases/download/v0.5.5/litestream-v0.5.5-linux-amd64.deb
sudo dpkg -i litestream-v0.5.5-linux-amd64.deb

# Docker
docker pull litestream/litestream:0.5
```

### Basic Replication

```bash
# Command line (single database)
litestream replicate /path/to/db.sqlite s3://bucket/db

# With config file
litestream replicate -config /etc/litestream.yml
```

### Restore Database

```bash
# Restore latest backup
litestream restore -o /path/to/restored.db s3://bucket/db

# Point-in-time recovery
litestream restore -timestamp 2024-01-15T10:30:00Z -o /tmp/db s3://bucket/db

# Restore to specific transaction
litestream restore -txid 1000 -o /tmp/db s3://bucket/db
```

### Check Status

```bash
# View all databases and their replication status
litestream status

# List available LTX files
litestream ltx /path/to/db.sqlite
```

## Critical Rules

These rules are essential for correct Litestream operation:

1. **Lock Page at 1GB**: SQLite reserves the page at offset 0x40000000 (1GB). This page must always be skipped during replication and compaction. The page number varies by page size:
   - 4KB pages: page 262145
   - 8KB pages: page 131073
   - 16KB pages: page 65537

2. **LTX Files are Immutable**: Once created, LTX files are never modified. New changes create new files.

3. **Single Replica per Database**: Each database can only replicate to one destination. Use multiple Litestream instances for multiple destinations.

4. **WAL Mode Required**: SQLite must be in WAL mode (`PRAGMA journal_mode=WAL;`)

5. **Use `litestream ltx`**: The `litestream wal` command is deprecated.

## Storage Backends

| Backend | URL Scheme | Example |
|---------|-----------|---------|
| AWS S3 | `s3://` | `s3://bucket/path` |
| S3-Compatible (R2, Tigris, MinIO) | `s3://` | `s3://bucket/path?endpoint=host:port` |
| Google Cloud Storage | `gs://` | `gs://bucket/path` |
| Azure Blob Storage | `abs://` | `abs://container@account/path` |
| SFTP | `sftp://` | `sftp://user@host:22/path` |
| NATS JetStream | `nats://` | `nats://host:4222/bucket` |
| WebDAV | `webdav://` | `webdav://host/path` |
| Alibaba OSS | `oss://` | `oss://bucket/path` |
| Local File | (path) | `/var/backups/db` |

## Configuration File Example

```yaml
dbs:
  - path: /data/app.db
    replica:
      url: s3://my-bucket/app-backup
      access-key-id: ${AWS_ACCESS_KEY_ID}
      secret-access-key: ${AWS_SECRET_ACCESS_KEY}
      region: us-east-1
      sync-interval: 1s
```

## When to Use This Skill

Use Litestream skill when:
- Configuring SQLite database replication to cloud storage
- Setting up disaster recovery for SQLite applications
- Troubleshooting replication issues (WAL growth, sync failures)
- Implementing point-in-time recovery procedures
- Deploying Litestream with Docker, Fly.io, Kubernetes, or systemd
- Understanding WAL-based replication concepts

## Skill Contents

- `concepts/` - Architecture, replication mechanics, LTX format, SQLite WAL, VFS support, compaction
- `configuration/` - Storage backend configurations (S3, GCS, Azure, SFTP, NATS, OSS, WebDAV, File)
- `commands/` - CLI command reference (replicate, restore, status, ltx, databases)
- `operations/` - Monitoring, troubleshooting, recovery, and heartbeat monitoring
- `deployment/` - Docker, Fly.io, Kubernetes, and systemd deployment guides
- `integrations/` - MCP server integration for AI tools
- `scripts/` - Validation and diagnostic helper scripts

## Common Issues

### WAL Growing Too Large
- Check sync interval (default 1s may be too slow for write-heavy workloads)
- Verify storage backend connectivity
- Check for checkpoint blocking (long-running transactions)

### Replication Lag
- Monitor with `litestream status`
- Check network connectivity to storage backend
- Review sync interval configuration

### Restore Failures
- Verify backup exists: `litestream ltx /path/to/db`
- Check storage backend credentials
- Ensure target directory is writable

## Links

- [Official Documentation](https://litestream.io)
- [GitHub Repository](https://github.com/benbjohnson/litestream)
- [Getting Started Guide](https://litestream.io/getting-started/)