First impressions of Claude Cowork, Anthropic’s general agent

Anthropic say that Cowork can only access files you grant it access to—it looks to me like they’re mounting those files into a containerized environment, which should mean we can trust Cowork not to be able to access anything outside of that sandbox.

Update: It’s more than just a filesystem sandbox—I had Claude Code reverse engineer the Claude app and it found out that Claude uses VZVirtualMachine—the Apple Virtualization Framework—and downloads and boots a custom Linux root filesystem.

I recently learned that the summarization applied by the WebFetch function in Claude Code and now in Cowork is partly intended as a prompt injection protection layer via this tweet from Claude Code creator Boris Cherny:

Summarization is one thing we do to reduce prompt injection risk. Are you running into specific issues with it?