sandbox

OpenAI has implemented a custom sandbox for its Codex coding agent on Windows after determining that existing Windows isolation tools—AppContainer, Windows Sandbox, and Mandatory Integrity Control—could not adequately balance safety and functionality. The solution uses synthetic SIDs and write-restricted tokens to constrain file writes and network access without requiring administrator privileges.

OpenAI developed a custom sandbox implementation for its Codex coding agent on Windows after existing tools like AppContainer and Windows Sandbox failed to meet requirements. The solution uses synthetic SIDs and write-restricted tokens to constrain file writes and network access without requiring administrator privileges.