Reliable Web Push Demo

A minimal Express + Service Worker project that supports:

• Persistent VAPID keys via environment variables.
• Background push delivery (works with tab closed/minimized after subscription).
• Subscription persistence in subscriptions.json.

Setup

npm install
node scripts/generate-vapid-keys.js

Copy .env.example to .env and paste generated values.

VAPID env options

You can configure keys either way:

1. Separate env vars:

VAPID_PUBLIC_KEY=...
VAPID_PRIVATE_KEY=...

2. Single env var:

VAPID_KEYS={"publicKey":"...","privateKey":"..."}

or:

VAPID_KEYS=publicKey:privateKey

At startup, the server logs:

• key source
• VAPID_PUBLIC_KEY
• VAPID_PRIVATE_KEY

Run

npm start

Open http://localhost:3000, click Enable notifications, then use Send push batch.

Endpoints

• GET /api/config -> public VAPID key and sending limits.
• POST /api/subscribe -> save/update browser subscription.
• POST /api/send -> send repeated push messages.