OpenAI Joins Anthropic: Codex Integrated into Claude Code

OpenAI Invites Itself to Anthropic: Codex Integrated into Claude Code

OpenAI has recently introduced a plugin that integrates its coding assistant, Codex, directly into Claude Code from Anthropic. This plugin offers standard code review, a more aggressive adversarial review that challenges weaknesses and design decisions, as well as the ability to transfer tasks in the background. This integration allows developers to meet where they already work, embedding Codex into their existing workflow.

Claude Code currently dominates the market, and rather than waiting for developers to turn to Codex, OpenAI has chosen to integrate its model directly into developers' work environments. Every review performed by the plugin utilizes OpenAI's infrastructure, generating usage and allowing developers to experiment with Codex's capabilities without changing tools.

A Strategy of Technological Convergence

This plugin is part of a broader strategic overhaul at OpenAI. According to a report from the Wall Street Journal, the company plans to refocus its resources on coding tools and enterprise clients. Fidji Simo, CEO of Applications at OpenAI, reportedly described the success of Claude Code and Cowork from Anthropic as an "internal wake-up call." OpenAI also plans to merge ChatGPT, Codex, and its Atlas browser into a single desktop application. Greg Brockman would lead this transition.

The previous strategy of launching too many products at once, including Sora, Atlas, and a hardware device, has slowed the company down. By focusing on a more targeted offering, OpenAI hopes to accelerate its development and better meet the needs of developers.

Features and Accessibility

The plugin offers three main features: a standard code review, an adversarial review that questions code weaknesses, and the ability to transfer tasks to Codex in the background. To use it, a subscription to ChatGPT (including the free tier) or an OpenAI API key is required, as well as Node.js version 18.18 or higher.

Unlike a standalone program, the plugin uses the existing Codex installation on the machine, with the same settings and credentials. Users can also enable a "Review Gate" that prevents Claude Code from finalizing changes until Codex has reviewed them.

A Digital Trojan Horse

By integrating Codex into Claude Code, OpenAI creates a direct touchpoint with its model, allowing developers to experiment with its capabilities without changing tools. This pragmatic approach aims to gradually acclimate users to the OpenAI ecosystem. The plugin is available on GitHub at openai/codex-plugin-cc and has already garnered over 3,700 stars, reflecting the growing interest from the developer community.