detectClientTool only matched the legacy "codex-cli" User-Agent, so the current codex-tui CLI and Codex Desktop (UA "Codex Desktop", originator "codex_work_desktop") fell through to null and lost native passthrough — their requests got re-translated, stripping/overwriting fields like reasoning.summary instead of forwarding the client body as-is. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>