OpenAI Codex CLI — Official Coding Agent

Key Features

• Lightweight Rust CLI — Fast startup, minimal resource usage
• Agent Skills support — Same SKILL.md format as Claude Code and Gemini CLI
• Custom slash commands — Turn markdown files into reusable commands
• IDE integration — VS Code, Cursor, Windsurf extensions
• Multi-model — GPT-5.2, GPT-5.1, GPT-5, o3, o4-mini

Custom Prompts

Create .codex/prompts/my-command.md to add custom slash commands:

---
name: review
description: Review code for bugs and improvements
---
Review the selected code for potential bugs, security issues, and improvements.
Focus on correctness, performance, and readability.

Skills

Codex supports the same Agent Skills format as Claude Code:

.codex/skills/my-skill/SKILL.md

Skills auto-activate based on context. Cross-compatible with Claude Code and Gemini CLI via agentskills.io.

FAQ

Q: What is OpenAI Codex CLI? A: OpenAI official coding agent CLI. Supports Agent Skills, custom prompts, and IDE integration. Open-source alternative to Cursor.

Q: How do I install OpenAI Codex CLI? A: Check the Quick Use section above for step-by-step installation instructions. Most assets can be set up in under 2 minutes.