Comet Lab Atlas

An open-source, offline-first desktop app for running AI models locally — a private ChatGPT alternative.

Jan is a desktop application that runs language models on your own machine. It downloads and manages open-weight models, serves them locally, and presents a clean chat interface — all without an account or a network connection.

It can also connect to hosted providers when you want them, but its reason for existing is the offline case: a usable assistant that keeps every message on the device.

Where it's ideally used

A fit for individuals or teams who want a local AI assistant with a hard guarantee that conversations never leave the machine.

Where it doesn't fit

Not built for multi-user deployment — for a shared internal assistant you want a hosted server app instead.