OpenAI has launched Codex's Black Screen Lock Takeover feature, which prevents visual eavesdropping and locks upon physical key press

According to Watchful AI monitoring, OpenAI's Codex Agent product has launched a locked-screen control feature. This feature enables users to remotely and securely take control of their Mac software from a mobile device when the Mac is locked and the screen is off.

To achieve secure remote control while the screen is locked, Codex will introduce an Apple-approved low-level assistive plugin into the macOS system, integrating deeply into the system-level unlock process. When a control request is initiated from a mobile device, this plugin silently and temporarily unlocks the system in the background to run the target application. During this period, all physical keyboard and mouse inputs are completely disabled, and a pure black overlay is projected onto all connected monitors, visually "blinding" the local screen, ensuring that the computer's display remains black and locked.

This background auto-unlock channel is subject to stringent security boundaries. It is only activated during a brief controlled period of mobile authentication, and cannot be invoked by any other local software or third-party processes. If the system detects any touch input on the local physical keyboard or mouse during operation, an instant alert is triggered, the background unlock state is revoked, the screen is locked, all automated actions are paused, and manual unlock by the user on-site is required.

Furthermore, for security against privilege escalation, this mechanism is essentially a restricted "invisible sandbox" that cannot take control of terminal applications, affect Codex itself, or perform unauthorized root privileges (Sudo) or approve system privacy prompts.