Lan Runner

Encrypted local messaging. Nothing in the middle.

Lan Runner finds nearby devices on the same LAN and opens encrypted peer-to-peer chat sessions. Your messages stay on the local network: no account, no central server, and no internet connection required.

Talk to someone who hasn't installed it.

Name the person and Lan Runner generates a folder holding one self-contained HTML file. Send it over; they open it in a browser on the same network and you have an encrypted conversation. Nothing is installed on their side, and nothing is downloaded at run time.

A guest reaches exactly one conversation. Never your peer list, your console, your diagnostics, or another guest. The gateway only exists while a usable invite does, and releases its ports the moment the last one is revoked or expires — make no kits and Lan Runner opens no LAN-facing port at all.

Sessions are sealed with AES-256-GCM under a key agreed per session by P-256 ECDH, with the invite token mixed in, so only someone holding what you sent can derive it. Phones connect over HTTPS because browsers only grant the Web Crypto API to a secure context; the certificate is self-signed, so a phone warns once before you tap through, and its fingerprint is shown for you to confirm out loud.

The folder is a bearer token: anyone with a copy can message you as that guest, so send it the way you would send a password. Invites expire on their own after seven days.