Building a safe, effective sandbox to enable Codex on Windows

OpenAI’s Codex team found that Windows does not offer a built-in sandbox that fits Codex’s open-ended developer workflow, so it is designing its own.

The team evaluated AppContainer, Windows Sandbox, and integrity labeling as ways to enforce safe command execution, but none met all requirements.

The goal is a real OS-enforced sandbox on Windows so Codex can stay both useful and safe in its default mode.

That matters because Codex needs to run developer tools on a user’s machine without weakening security boundaries.