Grux OS is one: a free, open source (MIT) Mac agent that runs on a local model with no account, or on your own Anthropic key, and connects to MCP servers as the Claude app does. The two overlap less than they seem. The Claude app is Anthropic's official app for chatting with Claude: it is free on the Free plan, needs a Claude account, sits in your dock with quick entry, and its desktop extensions connect Claude to your files, browser and apps. Pro is $20 a month. Grux OS is a free, open source (MIT) agent for macOS with no account. It runs on a local Ollama model with no key, or on your own API key, including an Anthropic key, and it acts on the mail, calendar, files and meetings already on your Mac from one Command Panel, with a shell whose every command can be undone. You can also change Grux itself: it writes work orders for Claude Code. Use the Claude app to talk to Claude. Use Grux for an agent you can run locally and rewrite.
| Grux OS | Claude desktop app | |
|---|---|---|
| Made by | DotcomJack, open source (MIT) | Anthropic |
| Account | None | A Claude account (the Free plan works) |
| Models | A local Ollama model, or your own key, Anthropic included | Claude, through your Claude plan |
| Works with your Mac | Mail, calendar, contacts, notes, files, meetings and an undoable shell | Files, browser and apps through desktop extensions |
| Price | $0, or what your own key costs | Free plan, or Pro at $20 a month |
| Can you change the app | Yes, it is open source and writes work orders for your coding agent | No, it is Anthropic's app |
The Claude app details are from Anthropic's download and pricing pages, checked on 2 October 2026.