OpenAI Codex April Update: Windows Sandbox Gets OS-Level Egress Rules and Headless Device Code Login

OpenAI Developers·medium signal

OpenAI's Codex CLI received a builder-relevant update in early April: Windows sandbox runs now enforce proxy-only networking with OS-level firewall rules (not just environment variables), preventing malicious code from bypassing network restrictions. Device code flow authentication enables headless login in SSH sessions, Docker containers, and CI/CD pipelines where browser callbacks fail. Additionally, 'codex exec' now supports prompt-plus-stdin for piped workflows.