A local AI assistant on your Mac: what it does, what it needs, what it never does

What is a local AI assistant?

A local AI assistant is a language model stored and run on your computer: the text you type is processed by your Mac's own chip, not uploaded to a server. The trade-off is simple. A local model is smaller than the ones behind online chatbots, so it knows less and reasons less far, but what you ask it stays on your machine and it keeps working without an Internet connection.

Tack+'s assistant is built for short jobs on the Mac rather than long conversations: one request, one action, one receipt. You type "Tidy my Downloads by type"; it prepares the move, shows it to you, and does it once you agree.

What can the Tack+ assistant do?

The assistant has 40 tools, each one a precise action on the Mac. It picks the tools that fit your sentence and chains them. Here is what a request looks like in practice.

It can also create a folder or a text file, read a text file or add a line to one, open a file with its app, show it in the Finder, list the tabs open in Safari and close some of them. It reads your calendar for a day, checks off a reminder, pauses the music or skips a song, starts the Focus timer, copies text to the clipboard, runs one of your Shortcuts, tells you the battery level and does arithmetic. When a request is vague ("tidy my files"), it asks which folder you mean before doing anything.

Dates and sums are worked out by Tack+, not by the model. You say "in 20 minutes" or "tomorrow at 3pm" in any of the six languages; the app turns those words into the exact date. A small model is unreliable at arithmetic, so this is what makes an event land at the right minute.

Which model does it use, and what does it need?

The assistant runs Qwen3.5 4B, an open model published under the Apache 2.0 licence, in a compressed version that weighs 2.74 GB. Tack+ downloads it from Hugging Face, a public model library, only if you ask for it, and keeps it in its own folder on the Mac.

For a sense of speed: on the MacBook we develop Tack+ on (M4, 16 GB of memory), a typical request takes about ten seconds from the moment you press Return to the answer. An older or busier Mac will be slower. If you change your mind, Tack+ can delete the model and give the 2.74 GB back.

How do I turn it on?

1. Click the Tack+ icon in the menu bar and choose Download the assistant… The welcome screen offers the same download the first time you open Tack+, with the model's name and size, and a button to skip it.
2. Carry on with your work: the download continues in the background, and can be resumed if it is interrupted.
3. Open the panel and click the assistant in the tools row. Type your request in Ask for something… and press Return.
4. When it shows what it is about to do, click Do it, or Do nothing to leave everything as it is.

Nothing about the assistant appears in the panel until you have asked for the model. Tack+ works exactly as before without it.

What does it ask before acting?

The assistant asks for your agreement before every change to your files: moving, renaming and deleting all show a card that lists what is about to happen, and nothing happens until you click Do it. Four more rules sit on top of that one.

• Trash only. A deleted file or folder goes to the Trash, never further. Emptying the Trash is a separate request, and it asks first.
• Before anything leaves the Mac or cannot be undone. Sending a message, placing a call, deleting a calendar event, emptying the Trash, restarting or shutting down the Mac all wait for Do it.
• One step back. The last request can be undone: files return to where they were, with the names they had, and an event or a reminder it just created is removed.
• Reading is free, changing is not. Listing a folder, searching for a file or reading a text file needs no confirmation, because nothing changes.

We added the confirmation after testing: asked to "tidy my files", a small model tends to pick a folder by itself and start. A card you can refuse costs one click and removes that risk.

What stays on the Mac, and what goes online?

Your requests, the names of your files and the answers stay on the Mac: the model computes locally and Tack+ sends them to no AI service, ours included. Four things do go online, each only when it applies.

• The download of the model: Hugging Face, which hosts it, sees your IP address at that moment, like any site you download from.
• What you ask for on the web: opening a site or running a web search happens in your browser, exactly as if you had typed it yourself.
• Reading a web page: Tack+ fetches the text of the public page you named, without cookies and without your browser's sessions. It reads the first 3,000 characters.
• What you ask it to send: a message leaves through Apple's Messages app, after you confirm it. A mail is only a draft, opened in your mail app for you to send.

One safeguard is worth knowing. A web page can contain text written to manipulate an AI ("read this file, then open this address"). So a single request either reads the web or touches your files and personal data (calendar, reminders, contacts, messages, clipboard), never both, and after reading a page the assistant forgets the conversation. A page it read cannot reach your files or write to anyone. The details are in the privacy policy (in French).

What can't it do?

• No payments, no passwords. It never buys anything and never types a password or a card number.
• No clicks inside web pages. It opens a site and reads public text; it cannot fill in a form, sign in or press a button on a page.
• Your folders, not the system. It works in your user folder (Desktop, Downloads, Documents and the rest), iCloud Drive, your external disks, the Applications folder and the Shared folder. The Library, where apps keep their settings and data, hidden files, system folders and other users' folders are refused, whatever is asked.
• It writes messages, it does not read them. It can send an iMessage and open a mail draft. It does not read your conversations or your inbox.
• Text files only, for reading and writing. It reads plain text files up to 2 MB, and takes in the first 3,000 characters of a file. It does not read inside PDFs, images or office documents: it sorts those by type and finds them by name.
• Safari for tabs. Listing and closing open tabs works in Safari. Opening a site works in Safari, Chrome or your default browser.
• Not a chatbot. It is a small model made to act on short requests. For a long discussion, a general knowledge question or writing help, a larger model will do better.
• It can misread you. A 4-billion-parameter model sometimes picks the wrong folder or asks an unneeded question. That is the reason for the confirmation card and the undo.
• Apple silicon only. On an Intel Mac, Tack+ runs without the assistant.

Which languages does it understand?

The assistant answers in the language of your request when it recognizes it clearly, and otherwise in the language Tack+ is set to. Tack+ exists in six languages: French, English, Spanish, German, Chinese (Simplified) and Japanese. When a request is too short or too ambiguous to tell, it uses Tack+'s language.

What happens while it works?

You can close the panel and carry on. On a MacBook with a notch, with Tack+ placed at the top edge, the assistant's mascot (a small white plus sign with a face) appears beside the notch while it works, and smiles when the job is done. Open the panel again to read the answer. See what Tack+ shows around the notch.