OpenSend
LiveFree, ad-free file sharing. Next.js 15 + Supabase + Capacitor + Electron. AGPLv3. Live at send.kovina.org.
1. Dual Transfer Methods: P2P and Cloud
OpenSend intelligently chooses between WebRTC peer-to-peer and cloud relay based on network conditions. In P2P mode, files transfer directly between devices with no intermediary. Adaptive chunk sizing (8KB, 16KB, or 64KB based on real-time throughput), sliding-window speed estimation, and exponential backoff with jitter ensure optimal transfer speed. If P2P fails, it falls back seamlessly to cloud relay without interrupting the transfer.
2. No-Account Guest Transfers
Open Send instantly — no sign-up, no login. The recipient connects via QR code scan or a 6-character code. Send up to 20 files at once, each up to 50 MB, for a total of 500 MB per transfer. Works between any two devices — phone to laptop, desktop to tablet, any combination.
3. Cross-Platform: Web, Android, Windows
Use the PWA at send.kovina.org, install the Capacitor Android app from the store, or run the Electron Windows desktop app with an NSIS installer. Deep links (opensend://) let other apps trigger transfers. File associations let you right-click any file and send it. Auto-update via GitHub Releases keeps the desktop app current.
4. Trusted Devices and Transfer History
Sign in with Google OAuth to register devices by fingerprint, rename them, and revoke access. Transfer history supports sent/received filters, favorites, and soft-delete. A sync toggle gives you optional cloud backup of your transfer history.
5. End-to-End Encryption and Security Hardening
Optional AES-256-GCM encryption with PBKDF2 key derivation (600,000 iterations) protects your files in transit. Content Security Policy, HSTS (2-year preload), X-Frame-Options DENY, rate limiting (5 guest transfers per minute per IP), and automated session cleanup via cron. A 22-item penetration test checklist is maintained in docs/security.md.
Part of the Kovina ecosystem
A collection of open-source tools built for ownership, permanence, and everyday use.
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