The free, open source alternatives to the ChatGPT app on a Mac split into two kinds. Chat clients give you a ChatGPT style window over a model you choose: Jan (Apache 2.0) runs local models fully offline, Enchanted (Apache 2.0) is a native SwiftUI client for Ollama, and Chatbox (GPL-3.0) talks to almost any provider. Ollama (MIT) is the engine underneath many of them and now ships its own Mac app. LM Studio is free for home and work but closed source. Grux OS (MIT) is the other kind: an agent rather than a chat window. It runs on a local Ollama model or your own key, and from one Command Panel it reaches the mail, calendar, files and meetings already on your Mac, plus a shell whose every command can be undone. Pick a chat client if you want to talk to a model. Pick Grux if you want the model to do things on your Mac.
| App | License | What it is | Best at |
|---|---|---|---|
| Grux OS | MIT | Native macOS agent | Acting on your mail, calendar, files and shell, with no account |
| Jan | Apache 2.0 | Desktop chat app | Fully offline chat with local models, on Mac, Windows and Linux |
| Ollama | MIT | Model runtime with a Mac app | Running local models that other apps, Grux included, connect to |
| Enchanted | Apache 2.0 | Native SwiftUI client | A light ChatGPT style window over Ollama on Mac and iPhone |
| Chatbox | GPL-3.0 | Desktop chat client | One window for many hosted providers and local models |
| LM Studio | Closed source, free for home and work | Model browser and chat app | Finding, downloading and testing local models |
Every chat client above answers questions well. None of them is built to act on your machine: they do not read your inbox, file a calendar event, or run a command in your project and let you roll it back. That is the job Grux OS is built for. If all you want is a private ChatGPT, Jan or Enchanted on top of Ollama is the shortest path, and Grux will happily share that same Ollama install.
Ollama is the common local backend. Install it once, pull a model, and Jan, Enchanted, Chatbox and Grux OS can all use it, so nothing leaves the Mac and the running cost is $0.
brew install ollama
ollama pull llama3.2:3b
brew install --cask dotcomjack/tap/grux