DropQR

Share files with a link + QR code that expires by time and by number of downloads. No sign-up.

Live: https://dropqr-mu.vercel.app

Stack

• Vercel — Express app (server.js) runs as a Vercel Function; public/ is served by the CDN.
• Vercel Blob (private store) — the file bytes. The browser uploads straight to Blob, so there is no 4.5 MB request limit.
• Neon Postgres — file records and download counters.

How it works

1. POST /api/uploads reserves an id and storage path.
2. The browser uploads directly to Blob (/api/blob-upload hands out a one-time token for that exact path only).
3. POST /api/uploads/:id/complete checks the file arrived, starts its timer and returns the link + QR code.
4. GET /d/:id uses up one download (atomic SQL update) and streams the file with its original name. Opening the share page /f/:id does not use a download.
5. Expired / used-up files are deleted from Blob and the database: alongside normal traffic (at most once a minute) and by a daily Vercel Cron job as a safety net.

Expiry: 5m, 10m, 30m, 1h, 6h, 12h, 1d, 3d, 7d. Download limit: 1–100.

Run locally

npm install
vercel env pull .env.local
npm run dev

Open http://localhost:3000. Local runs use the same Neon database and Blob store as production.

If you change client/blob-upload.js or upgrade @vercel/blob, rebuild the browser bundle:

npm run bundle

Environment variables

Variable	Set by	Meaning
DATABASE_URL	Neon integration	Postgres connection
BLOB_READ_WRITE_TOKEN	Blob store	Needed to issue browser upload tokens
CRON_SECRET	You	Protects /api/cron/cleanup
MAX_FILE_MB	Optional	Max upload size (default 100)
BASE_URL	Optional	Force the address used in links/QR

Deployment steps (Arabic): see DEPLOY.md.