Meta's Muse agent now reaches the files and messages on your Mac and acts on them
Zuckerberg announced it himself in a post, two days after he argued that every lab should set its own pace instead of agreeing on one.
Mark Zuckerberg posted on September 17, 2026 that Muse for Mac was out that day. Meta's agent had been on phones and the web since September 8, so this puts it on the machine where people keep their actual work.
Muse takes the task rather than answering a question about it. It can open a browser and fill out forms on someone's behalf, and it keeps working after the app is closed (coming back when it wants an approval, like before it sends an email).
- Works across
- Apps, files, calendar, notes and messages
- Muse launched
- September 8, 2026
- Runs on
- Muse Secure VM, a dedicated virtual machine
- Gatekeeper
- A separate Sentinel agent approves what reaches the internet
- Rollout
- In the US, on iOS, Android and muse.ai
What Meta has actually described
Meta's newsroom page for Muse, from September 8, 2026, lists iOS, Android and muse.ai, with glasses coming. No Mac on it. Zuckerberg's post is where the desktop version gets described, and the description runs to one sentence.
He wrote the announcement rather than sending it through the newsroom, which apparently makes this post the closest thing to documentation for now.
Muse for Mac is out today! It works across apps, files, calendar, notes, and messages on your computer. You control what it can access. The team is shipping fast. Download at
On phones, Muse checks out with Link built by Stripe, using a one-time-use card so real card details stay hidden, and 1Password support is coming so the agent can use logins a person already has. Whether the Mac app carries all of that, I couldn't find spelled out anywhere.
The box it runs in
Muse lives on what Meta calls Muse Secure VM, a dedicated virtual machine in the cloud holding the agent and the data for any service a person connects. A separate Sentinel agent sits on that same machine, kept apart from Muse at the system level.
Nothing Muse does reaches the internet unless the Sentinel approves it, and it asks the person for permission when needed.
Credentials go into secure storage, so Muse can use a password without seeing it (including one a person types into the browser themselves). Meta says the agent shows a complete audit trail of everything it has done and plans to do. Granted, all of that is Meta's own description of its own machine.
What surprised me is that the desktop app didn't get its own writeup. Meta published separate posts on how it built safety into Muse and how it designed Muse, then put the Mac launch out in a post on X.
Two days earlier
Zuckerberg had already given his answer to the pacing argument running through the industry. "Every lab has the responsibility and incentive to move at the pace required to train its models safely, and the ability to take its own actions to ensure that happens," he wrote on September 15, 2026. Muse reached the Mac two days later.
Meta says Muse Confidential VM comes later this year, with the whole virtual machine encrypted under a key only the person holds (so not even Meta can get into it).