Meta launches Muse for Mac: an AI agent that works directly on your files and apps

Meta is rolling out Muse for Mac, the first desktop version of its personal AI agent. The agent handles cross-app tasks without you copying and pasting context by hand. The download is free, US-only for now, and joins the mobile, web, and WhatsApp releases that dropped September 8 and shot to the top of the US App Store charts.

Here is how it works in practice. Muse for Mac plugs into local files, Mail, Messages, Calendar, and Notes — each in its native app. Instead of feeding the agent a prompt stuffed with copied text, it gathers context on its own. A calendar event, an email thread, a document in a folder, a WhatsApp message can all feed into a single task. Meta's examples: organizing folders, filling a form from data scattered across files, summarizing a day by blending emails, messages, and notes. The work is asynchronous; the agent keeps running in the background even with the window closed. You can start a task on your phone, pick it up on the Mac, and push it to WhatsApp without losing the thread.

Permissions are the critical piece here. Local access raises the risk floor, so the model is opt-in. Full Disk Access is entirely optional. You decide what the agent sees and can toggle it in settings at any time. Destructive or outward actions — deleting files, sending messages — require explicit approval. Muse can sort a folder freely but stops before deletion; it can draft a summary but asks before sending.

Under the hood: Muse Spark and Secure VM. The agent runs on Muse Spark, Meta's most advanced model to date, built for real-world agent work. The same model powers Muse Code, the coding agent for Mac and Windows. On the cloud side, each user gets a dedicated, isolated Muse Secure VM — no other agent can reach it. A separate Sentinel agent runs on that same VM, separated at the system level, and it alone approves internet access. There is a clear caveat: the isolation prevents cross-user leakage, not Meta itself from accessing data when needed to operate the service. Meta plans to launch Muse Confidential VM later in 2026, encrypting the entire VM with a key only the user holds. In the meantime, the company is running a public bug-bounty program for Muse.

Launch limits: the service is free up to 100 million tokens per week, and, as noted, US-only for now. This is a hosted service, not an open model you can run locally. For anyone who wants an agent that actually does things on the computer without uploading everything to the cloud, it's practical progress. For anyone who demands full privacy without vendor dependence, the future Confidential VM remains a promise not yet delivered.