Replicating Claude Code's Plan Mode with Codex Skills: A Feasibility Study
Published:Jan 1, 2026 09:27
•1 min read
•Zenn OpenAI
Analysis
This article explores the challenges of replicating Claude Code's sophisticated planning capabilities using OpenAI's Codex CLI Skills. The core issue lies in the lack of autonomous skill chaining within Codex, requiring user intervention at each step, which hinders the creation of a truly self-directed 'investigate-plan-reinvestigate' loop. This highlights a key difference in the agentic capabilities of the two platforms.
Key Takeaways
Reference
“Claude Code の plan mode は、計画フェーズ中に Plan subagent へ調査を委任し、探索を差し込む仕組みを持つ。”