Muse for Mac: What Meta's Mac App Can Do, Permissions and Security

Muse for Mac is Meta's free desktop app for the Meta Muse personal agent. It lets Muse work with your files and with Messages, Notes, Reminders, Mail and Calendar, and you set each app to Off, Read only or Read and interact. It asks before sending email or buying anything. It's available in the US and Canada.

It launched September 17–18, 2026 and shares the weekly usage limit of your Muse plan. In its first week a researcher disclosed a zero-day in the app, and Meta hot-fixed it on September 22. The details are below, because the lesson still applies.

What does Muse for Mac do?

The Muse agent normally lives in a cloud VM. The Mac app extends it to your own computer. Meta's announcement, quoted by 9to5Mac, says: "It works across apps, files, calendar, notes, and messages on your computer. You control what it can access."

That opens tasks the cloud agent can't do alone:

• Find, read or update files on disk. Meta's own launch post from the Muse account pitched organizing downloads and finding lost files.
• Read an iMessage thread and draft a reply.
• Turn an email into a Reminder or a Calendar event.
• Pull notes from the Notes app into a document.

At Connect on September 23, Meta announced Mac computer use, so Muse can operate "any app on your Mac" (Meta). Alexandr Wang, Meta's chief AI officer, framed it as: "You can walk away from your computer and it keeps working for you on all the jobs you lined up" (TechCrunch).

Computer use isn't switched on for everyone yet. A static teardown of the Mac app (codename Endo) found a full computer-use agent already in the public build, held back by five server-side feature flags. On September 25 Meta opened an early access program for the Connect features, including the Mac expansion. You join by asking Muse: "Can you let the Muse team know I want to be part of the Muse early access program?"

How to download and install Muse for Mac

1. Download the app free from ai.meta.com/muse/download.
2. Sign in with the Meta account you use for Muse. If you haven't set up Muse yet, do it on your phone first: how to get started with Muse.
3. Grant only the macOS permissions you need (next section).
4. Set each app to Off, Read only or Read and interact.

The Mac app draws from the same weekly allowance as the phone app, and paid plans raise the limit: Power at $20 a month and Max at $100 a month (see Muse pricing).

System requirements. Meta hasn't published a minimum macOS version. One builder says the app ships for Apple silicon only and built a remote-control bridge for Intel Macs so the cloud agent can still click and type on older machines. Treat that as the author's report, not a Meta spec.

What permissions does Muse for Mac need?

Meta's help page lists three macOS permissions:

Permission	Why Muse wants it	Grant it?
Full Disk Access	"so your agent can find, read or update files"	Only if you need file tasks
Automation	"so your agent can perform actions on apps that store information locally"	Needed for Read and interact
Notifications	"so your agent can tell you when a task it was working on is done"	Low risk

Full Disk Access is the big one. It lets an app read almost everything in your user account, including other apps' data. MarkTechPost's walkthrough notes it's optional, and it's the first thing to leave off.

Per-app controls: Off, Read only, Read and interact

For iMessage, Notes, Reminders, Mail and Calendar, you choose one of three levels:

• Off: the agent can't access that app's data.
• Read only: "your agent can read that information when you ask it something, but can't do anything in the app."
• Read and interact: "your agent can read that information and perform actions in the app."

A sensible start is Read only for Mail and Messages, and Read and interact for Reminders and Calendar, where mistakes are cheap to undo. Move Mail up only once you trust its drafts.

Built-in safeguards

Per Meta's help page:

• Muse asks for confirmation before "important action[s], such as sending an email or making a purchase."
• Deleted files go to the Trash, so you can recover them.
• You can turn off use of your data for AI training in Settings.

Meta's own warnings are worth reading twice: "Your agent may be inaccurate or take unexpected actions. Monitor its actions carefully," and "Computer use gives your agent broad reach across your Mac, so only grant access you're comfortable with."

Is Muse for Mac safe? The zero-day and the Sep 22 fix

On September 21, Patrick Wardle disclosed a zero-day, first written up by Malwarebytes. An undocumented debug setting in the app's local preferences controlled which server handled dictation. Any local process could change it and redirect dictation to an attacker's server, exposing voice prompts and the Muse account auth token.

Meta hot-fixed it shortly after midnight on September 22 by removing the setting from production builds (Gizmodo, Unite.AI). Wardle confirmed it: "Hooray, hot-fixed!"

The two sides still disagree on how serious it was. Meta's David Singleton called it "a local privilege escalation attack, not a remote exploit," meaning malicious code had to be on the Mac already. Wardle answered that ClickFix-style tricks, where someone is talked into pasting one command into Terminal, get that code there easily, and he showed a hijacked agent could reach more than 50 sensitive commands.

The fix closed that hole. The broader lesson stands: an agent that can read your mail, messages and payment tools is a bigger prize than a normal app. So:

• Keep macOS and Muse updated. Meta hasn't said whether fixes install automatically, so check.
• Don't grant Full Disk Access unless you need it.
• Avoid giving Muse email, chat, payments and device permissions all at once.
• Never paste a Terminal command someone sends you "to fix Muse."

More on Meta's security model in Muse security and privacy.

What's inside the Mac app

Mahdi Salmanzade published a static privacy teardown of Muse 3.0 for macOS alongside the phone apps. It documents shipped tools for iMessage, WhatsApp, Mail and screen control, background sync, and a bundled Chrome extension. That's a useful map of what the app can reach, whether or not every tool is switched on for you.

Muse for Mac alternatives builders made

Before and alongside Meta's app, people bridged Muse to their Macs themselves:

• Muse Mac Connector is an open-source menu-bar app that exposes an authenticated tool set over a Cloudflare tunnel, so Muse takes user-approved actions only.
• muse-fileapi exposes whitelisted folders with two-phase writes and an audit log.
• A Reddit user's bridge let Muse read a training run off the Terminal and lock the Mac from a phone.
• Calliope is an unofficial native macOS client for Muse, shipped as a notarized DMG.

The first two give you narrower, auditable access than Full Disk Access, which some people will prefer. If you'd rather run a model on your Mac with nothing leaving it, Muse Glimmer runs on Apple silicon: see running Muse Glimmer locally.

Should you install Muse for Mac?

If you already use Muse and want it working on your files and Apple apps, the per-app controls are well designed and the zero-day is patched. Start with Read only, skip Full Disk Access unless you need it, and grow access as it earns trust. If you're new to Muse, start on the phone or in WhatsApp, where there's nothing local to expose.

Frequently asked questions

Is Muse for Mac free?

Yes. The download is free and uses the same weekly usage limits as your Muse account. Paid plans, Power at $20 a month and Max at $100 a month, raise those limits.

What apps can Muse access on a Mac?

Meta lists iMessage, Notes, Reminders, Mail and Calendar, each set to Off, Read only or Read and interact, plus files through Full Disk Access. Meta announced computer use for any Mac app at Connect 2026, and it's rolling out through an early access program.

Is Muse for Mac safe to install?

It asks before sending email or buying things and moves deleted files to the Trash. A dictation zero-day disclosed on September 21, 2026 was hot-fixed by Meta on September 22. Keep the app updated and grant the fewest permissions you can.

Does Muse for Mac work on Intel Macs?

Meta hasn't published system requirements. A community developer reports the app ships for Apple silicon only and built an unofficial bridge so Muse's cloud agent can control an Intel Mac.

Is Muse for Mac available outside the US?

It follows Muse's availability: the US and Canada, for adults 18 and older. No UK, EU or India date has been announced.