Icon of Gupt app on Umbrel App Store

Gupt

Self-hosted, end-to-end encrypted messenger built on Nostr

Get it on umbrelOS
Version2026.05.13
CategorySocial
Source codePublic
Developed bybesoeasy3 apps
Submitted bybesoeasy5 apps
Compatible withumbrelOS 0.5 or later

Gupt is a privacy-first, self-hosted messaging app built on Nostr relays with WebRTC calls — a free and open-source alternative to Telegram, Signal, WhatsApp & Discord.

Key features include:

  • Anonymous — no phone number, no email, no account required
  • End-to-end encrypted direct messages
  • WebRTC voice & video calls
  • Encrypted media uploads via decentralized file storage
  • Group rooms via Nostr relays
  • Local-first with offline cache (IndexedDB)
  • Installable PWA

Gupt is fully client-side with no backend — it connects directly to public or private Nostr relays. Your keys, your messages, your privacy.

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