OpenAI Introduces Codex Plugin for Claude Code, Enabling Cross-Company AI Delegation

OpenAI has introduced a Codex plugin for Anthropic's Claude Code, allowing users to invoke OpenAI's Codex directly from within the Claude Code environment to review code or delegate tasks, according to a post by Vaibhav Srivastav on Monday. The integration is notable for crossing company lines: Claude Code is Anthropic's command-line coding assistant, while Codex is OpenAI's code-generation and reasoning model. The plugin effectively lets Claude Code users offload specific tasks to a competing AI system without leaving their workflow. The move reflects a broader pattern of AI tooling becoming composable across vendors. Developers increasingly work with multiple AI models simultaneously, selecting different systems for different tasks based on capability, cost, or speed. Plugins and APIs that enable cross-model delegation lower the friction of that multi-model workflow. Claude Code, launched by Anthropic as a terminal-based agentic coding tool, has gained traction among software engineers for tasks including codebase navigation, refactoring, and automated pull request generation. Codex, OpenAI's coding-focused model, is separately available via API and through GitHub Copilot integrations. The plugin architecture in Claude Code allows third-party tools to extend its capabilities. OpenAI building and publishing a plugin for a direct competitor's product is an unusual distribution move, suggesting both companies see interoperability as a growth strategy rather than a threat. Neither OpenAI nor Anthropic issued formal press releases at time of publication. The plugin was surfaced via a post from an AI researcher tracking model ecosystem developments.