Svelte SQLite PWA Template

A template for building offline-first Progressive Web Apps with SvelteKit, SQLite (via OPFS), and push notifications.

Features

• SQLite with OPFS - Persistent client-side database using Origin Private File System
• PWA Ready - Service worker, manifest, and installable on all platforms
• Push Notifications - Works on desktop and mobile (including iOS when installed)
• Svelte 5 - Latest runes-based reactivity
• TypeScript - Full type safety
• Tailwind CSS v4 - Utility-first styling
• Vitest - Unit and component testing

Quick Start

# Clone the template
git clone https://github.com/YOUR_USERNAME/svelte-sqlite-pwa.git my-app
cd my-app

# Install dependencies
bun install

# Start development server
bun run dev

Open http://localhost:5173 in your browser.

Development

# Start dev server
bun run dev

# Run tests
bun run test

# Type check
bun run check

# Lint and format
bun run lint
bun run format

Building for Production

# Build the app
bun run build

# Preview production build
bun run preview

Project Structure

src/
├── lib/
│   ├── db/           # SQLite database layer
│   │   ├── sqlite.ts        # Main DB API
│   │   ├── sqlite-worker.ts # Web Worker for SQLite
│   │   └── index.ts         # Exports
│   └── notifications/ # Push notification utilities
├── routes/
│   └── +page.svelte   # Demo page
└── app.d.ts          # TypeScript declarations

SQLite Usage

import { db } from '$lib/db';

// Initialize (call once on app start)
await db.init();

// Execute statements
await db.exec(`
  CREATE TABLE IF NOT EXISTS users (
    id INTEGER PRIMARY KEY,
    name TEXT NOT NULL
  )
`);

// Insert/Update/Delete
const result = await db.run(
  'INSERT INTO users (name) VALUES (?)',
  ['Alice']
);
console.log(result.lastInsertRowid);

// Query multiple rows
const users = await db.query<{ id: number; name: string }>(
  'SELECT * FROM users WHERE name LIKE ?',
  ['%ali%']
);

// Query single row
const user = await db.queryOne<{ id: number; name: string }>(
  'SELECT * FROM users WHERE id = ?',
  [1]
);

OPFS Persistence

The database automatically uses OPFS (Origin Private File System) when available, providing persistent storage that survives page refreshes and browser restarts. Falls back to in-memory storage on unsupported browsers.

Requirements for OPFS:

• Modern browser with OPFS support
• Served over HTTPS (or localhost)
• COOP/COEP headers (configured in vite.config.ts)

Push Notifications

import { notifications } from '$lib/notifications';

// Initialize (checks platform capabilities)
notifications.init();

// Check status
if (notifications.canRequest) {
  await notifications.requestPermission();
}

// Send test notification
if (notifications.isGranted) {
  await notifications.sendTest();
}

iOS Note: Push notifications on iOS require the app to be installed to the home screen (Add to Home Screen from Safari).

Configuration

Vite Config (vite.config.ts)

The template includes:

• COOP/COEP headers for SharedArrayBuffer (required by SQLite OPFS)
• Worker configuration for ES modules
• PWA plugin with workbox caching

PWA Manifest

Edit the manifest in vite.config.ts to customize:

• App name and description
• Theme colors
• Icons

Browser Support

Platform	SQLite OPFS	Push Notifications
Chrome/Edge 102+	Full	Full
Firefox 111+	Full	Full
Safari 15.2+	Full	Full
iOS Safari 17+	Full	Home screen only
iOS Safari 16.4+	Limited	Home screen only

License

MIT