Codex
OpenAI's coding agent, the ChatGPT-side counterpart to Claude Code. Released in April 2025, it writes code, fixes bugs, and works through tasks on a project for you, on your machine or in OpenAI's cloud. It is available inside ChatGPT on the web, in the terminal, as a desktop app, and in code editors.
In plain English
Codex is OpenAI’s version of the agent that does the work instead of describing it. Point it at a project, tell it what you want, and it edits, runs, and reports back.1 If you pay for ChatGPT, this is the coding agent you already have.
In the real world
- Codex inside ChatGPT on the web, where you hand off a task and come back later.1 That’s the place to start.
- The terminal version, the text-only command window, for people who live there.
- A developer saying “I had Codex do it” about a chore they didn’t want to do.
- The place developers launch OpenAI’s always-on Dots.2
When to use it
- You’re on a ChatGPT plan and want an agent without buying another subscription.
- Tasks you can describe clearly and check afterwards.
When not to use it
Vague tasks. Like every coding agent, it will build exactly what you said. Write the brief first.
Good, bad, ugly
- Good: included with the subscription most people already have.
- Bad: the name has been used for different OpenAI products over the years, so old articles mislead.
- Ugly: cloud agents work on a copy of your project you can’t see while it runs. Review the result like you’d review a stranger’s.
Key facts
- Made by
- OpenAI
- Released
- April 2025, as a command-line tool first
- Runs in
- ChatGPT on the web, the terminal, a desktop app, and code editors
Common questions
Is Codex the same as ChatGPT?
Same company, different job. ChatGPT chats. Codex works on code and files, on your machine or in OpenAI's cloud.
Codex or Claude Code?
They do the same kind of work. Pick the one that matches your subscription and the model you prefer, then stick with it long enough to learn it.
Do I need to code to use it?
It's built for developers, but the tasks don't have to be code. 'Turn this folder of exports into one clean spreadsheet' is a Codex task. Which ChatGPT plans include it changes; check OpenAI's plan page.
References
- OpenAI CodexWikipediaView source
- OpenAI launches dots, its bubbly agentic avatarTechCrunch · 2026-09-29View source