OSHI: Offline Messenger

Chat with no internet, no SIM, no phone number. End-to-end encrypted one-to-one chats. Plus on-device AI.

OSHI is the private messenger that keeps working when the internet doesn't.

Chat, call and share over a Bluetooth + Wi-Fi mesh — no SIM, no phone number. When you do have a connection, everything syncs seamlessly. When you don't — at a festival, on a plane, hiking, travelling abroad, or in an outage — OSHI keeps working by hopping messages from phone to phone.

WHY OSHI • Works offline — a Bluetooth/Wi-Fi mesh reaches people near you with zero signal • One-to-one chats and calls end-to-end encrypted — X3DH + Double Ratchet • No phone number, no SIM, no email required • On-device AI assistant that runs entirely on your iPhone • Voice and video calls • Group chats, voice notes, photos, files, live location • Self-destructing "view once" media • Your keys stay on your device — we can't read your messages

HOW FAR THE MESH REACHES Offline mesh is short range. Both phones need OSHI open to find each other, roughly 100 m apart in the open and much less through walls. It reaches further only when other people nearby also have OSHI open to pass the message along. If no one is in range, OSHI sends over the internet instead.

PRIVATE BY DESIGN One-to-one messages are encrypted before they leave your phone and can only be read by the person you send them to. Group names and member lists are visible to our servers, and messages bridged to other devices or LoRa radios are not encrypted by that link.

ON-DEVICE AI The assistant runs locally on your iPhone — your prompts and its replies never leave the device. Like any AI, it can be wrong, so check anything that matters.

BUILT FOR THE REAL WORLD Festivals, crowded venues, hikes, flights, travel abroad, power cuts and dead zones: when the network drops, OSHI keeps the conversation going with the people around you.

Download OSHI and take your conversations off the grid.