Meta's Muse gives every user a persistent cloud computer
The AI agent, now Meta's most-promoted app, runs each user's own Ubuntu Linux VM, and reporters say prodding it also exposes files the company did not mean to show.
Meta's Muse agent gives every user a free, persistent cloud computer running Ubuntu Linux. Users can install software and browse the web inside it. They can also write and compile code, Meta's David Singleton, the company's vice president of engineering, said.
Muse has drawn more than 500,000 users in its first week. It reached number one on the US App Store on September 18 and the Google Play Store the next day, The Decoder and TechCrunch reported. Download estimates vary by tracker. Sensor Tower put the total at 3.4 million and Apptopia at 4.3 million. Appfigures's estimate was lower, near 2.3 million.
Meta has pushed the app hard internally, TechCrunch reported. House ads for Muse began a day after launch, and by September 22 the app ranked among Meta's top 10 by ad spend. Promotion also expanded to outside platforms such as Reddit and TikTok, the outlet said. Daily active users rose 27% in a single day after Meta's Connect announcements.
Each user's session runs in an isolated "Runtime Cell" with its own file system. An external process Meta calls Sentinel watches for risky actions from outside that cell. A built-in file explorer also lets users inspect every file, including Muse's own binaries. The Verge reported that prodding the system exposed details it "wasn't supposed to reveal," without saying what those details were.
The writer John Gruber, quoted by developer Simon Willison, called Muse "the first consumer-accessible agentic AI system." He said its friendly packaging undersells the risk. "I don't think people realize how powerful — and thus dangerous — Muse is, especially if it's running on your Mac," Gruber wrote.