the app to have that conversation.

About mono

mono is a radically private messaging app built on the principle of Digital Monogamy — one conversation at a time. No sign-up required. No name, email, phone number, or personal data. No profile picture, no history, no trace.

How it works

Share your unique rotating key or enter someone else's to start a conversation. Each key is 18 characters, rotates every 3 minutes, and connects exactly 2 people. Once connected, you enter an exclusive 1-on-1 encrypted chat.

Privacy by design

Every message is end-to-end encrypted using Curve25519 ECDH + AES-GCM. Not even mono's servers can read your messages. Only the last 15 messages are visible — older messages are permanently deleted. If there's no activity for 18 hours, the entire conversation self-destructs.

Features

• End-to-end encryption (E2EE) with Curve25519 + AES-GCM
• Anonymous authentication — no sign-up, no identity
• Ephemeral messages — only last 15 visible, FIFO deletion
• 18-hour auto-destruct for inactive conversations
• View-once media — images, videos, and files viewable only once
• Screenshot protection — content hidden during screen capture
• Deep Wipe — instantly delete everything for both users
• Rotating keys — new 18-character key every 3 minutes
• No notifications, no badges, no alerts
• Text, images, videos, and files only — no calls, no voice notes

Available on

mono is available on iOS and macOS. Download from the App Store.