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What is OpenAI Codex?
Codex is a coding agent from OpenAI that can read your code, make changes and run tasks for you.
- Category Agents & tools
- Also called OpenAI Codex, Codex CLI
- Updated 20 Oct 2026
Codex, explained simply
Codex is an AI coding tool made by OpenAI. You give it a job, like fixing a bug, and it works on your code.
It matters because it can handle routine coding chores while you do other things. You then review what it did.
For example, you could ask it to add tests to a project. It writes them, runs them and shows you the changes.
You can use it from the command line on your own computer, and OpenAI also offers other ways to use it.
On ITG Now, our daily AI news covers coding agents like Codex, and our free tool guides show how to install similar tools.
Related terms
AI coding agentChatGPTCLIClaude CodeAPI key
Where you'll see it on ITG Now
- GuidePonytail Skill: Make Your AI Coder Write Less Code (2026)
- GuideArchify: Free AI Diagram Generator for Claude and Codex (2026)
- GuideOpenDesign: Free Open Source AI Design Tool for Teams
- GuideHallmark: Free AI Web Design Skill for Claude Code (2026)
- GuideHindsight: Free AI Agent Memory That Learns (2026 Guide)
- GuideSuperpowers: Free Claude Code Skills That Plan First (2026)
Questions people ask about Codex
Is Codex free?
It depends on your OpenAI plan or API use. Check OpenAI's site for current options.
Codex vs Claude Code: what is the difference?
Both are coding agents. Codex comes from OpenAI and Claude Code comes from Anthropic.
Is Codex safe to run on my files?
Review its changes and keep a backup or use version control. It is a tool that edits files, so look before you accept.