Codex Plugin for Claude Code

Official OpenAI plugin released March 2026 that brings Codex (GPT-5.4) inside Claude Code via /codex commands. Installs via plugin marketplace with three commands, works with a free ChatGPT subscription, and exposes functions including /codex review, /codex adversarial-review, and /codex rescue. Read-only review commands diff uncommitted changes or branches; adversarial review pressure-tests implementations for failure modes and tradeoffs.

Key facts

  • Installed via three commands that add the OpenAI marketplace and plugin
  • Usable for free with a ChatGPT subscription
  • Provides /codex review, /codex adversarial-review, /codex rescue, and other functions
  • Review and adversarial review are read-only and do not modify code
  • GPT-5.4 beats Opus 4.6 on most coding benchmarks except SWE-bench
  • Power-user pattern: plan/build with Opus, review with Codex

Source references

  • [src-004] Nate Herk cluster — Nate Herk — Claude Code cluster (21 videos)

– Videos referenced: B2Kh_ZoLVTM

Robin Cartier perspective

This page is part of Robin Cartier's working AI knowledge graph: a practical research layer for production AI, recommendation systems, experimentation, GEO, and agentic web readiness.

The useful next step is to connect this concept back to applied product leadership and operating models.

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