Sandboxing and Computer Use: Isolation for What You Cannot Pre-Approve

Containment, part two. Scoping tools handles the calls you can enumerate; sandboxing handles the ones you cannot — agent-written code, shell commands, and browsers pointed at the open web. The isolation ladder, sandbox hygiene, and the containment rules for computer use.

Content current as of 2026-09.

Lessons

1. “Just run the code” is a security decision
2. The isolation ladder: what each tier stops, and what escapes
3. Sandbox hygiene: what is inside the box matters as much as the box
4. Computer use and browser agents: injection at the width of the web
5. Picking a tier for five real workloads