Felix Rieseberg explains Cowork's move of its virtual machine to the cloud

Quoting Felix Rieseberg

In the new version of Cowork, both model inference and the virtual machine run in the cloud. The old version ran inference in the cloud but executed tool calls in a virtual machine on the user's computer. Simon Willison cites Anthropic's Felix Rieseberg saying each session gets its own sandbox with no shared state, and the desktop app handles tool calls when device files are needed.

Why it matters: Cowork moves its virtual machine off the local machine, addressing disk, battery and performance load and tasks that stopped when the laptop was closed.