Codex CLI on GPT-5.5 Tops Terminal-Bench 2.1 at 83.4%

OpenAI Codex Changelog·medium signal

OpenAI shipped a Codex refresh on GPT-5.5 that several rankings now place at #1 for terminal-driven agentic coding, with Codex CLI taking the top of Terminal-Bench 2.1 at 83.4%. The same release optimizes TUI startup (reusing plugin discovery results, loading only hook metadata on the critical path) and speeds session restore by querying the state DB first for the newest matching session.