Unexpected Alliance: OpenAI Integrates Codex into Anthropic's Claude Code

The AI market is reaching a new level of maturity as OpenAI has released an open-source plugin allowing Codex to be triggered directly from Claude Code—the AI agent of its primary competitor, Anthropic.

The plugin introduces slash commands for code review (/codex:review) and architectural stress testing. Developers can now leverage the best of both worlds: Claude’s analytical skills and Codex’s (GPT-5.4) robust coding power within a single workflow. This move highlights a growing trend toward cross-platform compatibility in the AI agent ecosystem. "We love the open ecosystem!" stated OpenAI’s leadership, signaling that user experience now transcends corporate rivalry.

This material was prepared by the "Amul Info" tech desk based on an analysis of open-source integrations from OpenAI and Anthropic.