Meta Releases Muse for Mac, a Personal AI Agent That Acts on Local Files and Native Apps

Mark Zuckerberg announced the Mac app on X, writing that it works across apps, files, calendar, notes and messages, that users control what it can access, and that "the team is shipping fast." Meta's chief AI officer, Alexandr Wang, announced the launch the same day. Muse itself is not new: it launched on September 8 in the United States across iOS, Android, the web and WhatsApp, and according to TechCrunch it quickly rose to the top of the U.S. App Store charts after that release. Meta describes Muse as a hosted consumer agent rather than an open model that users can self-host.

On the Mac, Muse can interact with a user's files, messages, calendar, notes and mail inside their native applications. Meta frames the product around everyday tasks that span several apps. A user can ask it to organize folders, fill in a form using information stored in files, or assemble an end-of-day summary from emails, messages and notes. The practical change is context gathering: where a conventional chatbot requires information to be copied and pasted into a prompt, Muse can potentially collate context held in different places on the computer, so a single task might touch a calendar event, a mail thread, a document and a Messages conversation.

Muse also runs asynchronously. Meta said the agent keeps working in the background even when the desktop window is closed, and that a task started on a phone can be checked from a laptop or nudged through WhatsApp, with Muse keeping the thread across devices.

Local access raises the stakes on permissions. Access to the computer is opt-in, and Full Disk Access is optional; users decide which permissions Muse receives and can change them at any time through Settings. Destructive or outbound actions are gated: Meta says sensitive actions such as deleting files or sending messages require approval first. In practice, Muse can sort a folder freely but must stop before deleting anything, and it can draft a summary but must ask before sending it.

Muse is powered by Muse Spark, which Meta calls its most capable model to date and which was built for real-world agentic work. The same model powers Muse Code, a coding agent available for macOS and Windows. The cloud side runs on Muse Secure VM, with Muse operating on its own dedicated computer in the cloud, contained so that no other user's agent can reach it. A separate Sentinel agent runs on that same machine, kept apart from Muse at the system level, and nothing Muse does reaches the internet unless the Sentinel approves it.

One caveat is stated plainly in the launch material: Secure VM isolates a user's data from other users, but it does not prevent Meta from accessing that data when necessary to operate the service. Meta plans to introduce Muse Confidential VM later in 2026, which would encrypt the entire VM with a key only the user holds. Meta also runs a public bug bounty for Muse. The product is free up to 100 million tokens per week.