Codex CLI's GPT-5.5 Refresh Adds Developer Mode for Browser Use With Chrome DevTools Protocol Access

OpenAI Codex Changelog·medium signal

OpenAI's latest Codex refresh adds a Developer mode for Browser use that gives the agent controlled Chrome DevTools Protocol (CDP) access for performance profiling and deep debugging of network traffic, console output, runtime errors, and page state. The update also lands an /init command in the in-app composer, customizable macOS Dock icons, and expanded Computer Use access controls. Recent rankings now put GPT-5.5 Codex at #1 among CLI coding agents.