what it is, what you can do with it and how to use it

Let’s explain to you what it is and how you can use ChatGPT Codexthe ChatGPT scheduling agent. This is an option with which artificial intelligence is not limited to answering questions or generating code, but can work more autonomously on programming projects.

We are going to start the article by explaining to you what exactly it is, so that you can understand that nonsense that it is a AI agent programming or software engineering. Then we will make a small list of what you can do, and we will finish by explaining to you in a basic and simple way how to use it.

What is ChatGPT Codex

Codex is one of the functions within ChatGPT, a programming agent. AI agents are programs that use AI to work autonomously. Instead of having to guide it step by step to do a task, you tell it what you want, and the agent will run in the background making decisions to do what you ask on its own.

In this case it is a scheduling agent. This means that you can ask him to write code and create a programbut also analyze project code, make modifications, or run tests to make sure everything is working correctly. It is capable of working in the cloud on your code repositories, executing each task in an isolated and secure environment.

Codex was launched in 2025 as an agent within ChatGPT, and evolved until in 2026 it began to have its specific application for computers. Below, uses specialized GPT programming modelsspecifically trained to understand and be able to analyze the code of complex projects, execute commands or verify their own work.

What you can do with Codex

In practice, Codex can work autonomously by performing multiple programming related tasksfrom writing code to reviewing it or testing it. These are the things you can do with this tool:

• Program without writing code: The most basic thing you can do with Codex is ask it to create an application, web or script. You define what you want and what you would like it to do, and this agent will write the code, test it in an isolated environment, and give you the result for you to review.
• Work on your GitHub projects: You can connect Codex to a repository to assign tasks such as fixing bugs, adding features, writing tests, or doing migrations and refactorings. Codex will deliver the changes to you in the form of pull request that you can accept or reject.
• Answer questions about code: You can give Codex a code, and then ask it questions related to it. You can ask it how it works, what a specific part of this code does, where it can make a mistake, or whatever you want. No longer to make changes, but to receive information.
• Review code and security: Codex can do code reviews to detect issues before they reach production, and in March 2026 OpenAI introduced Codex Securityan agent specialized in detecting and proposing corrections to vulnerabilities.
• Automate repetitive tasks: If you use Codex in its desktop application, you can schedule automations at specific times to perform tasks such as generating daily reports or reviewing bugs, and whose results reach a review queue.
• Control your computer: Newer versions of the desktop app allow Codex to use applications on your computer and browse the web to complete tasks. Of course, every time he has to take a delicate step he will ask you for explicit permission to do so.
• Knowledge tasks that are not code: May perform prototyping, documentation, data analysis, or research. Codex is evolving to not only be a programming agent, but can also help you with “office tasks.” This is because almost everything a computer can do can be solved with code.

How to use Codex

Codex is included in all ChatGPT subscriptions, including its free version. Of course, access from the free version and the cheapest subscriptions is limited.

You have two methods to download Codexsince it works as a standalone desktop application. You can go to the download page by clicking on the option Codex from the left column of the website or by entering directly on the page chatgpt.com/codex.

you also have the option to use Codex in the cloud with the website of chatgpt.com/codex/cloud. Here, you will be able to connect the tool on GitHub and interact with your projects.

Once inside Codex, you’ll see a text field with options to code or ask questions. One is to ask him to do programming tasks, and another to ask him questions related to the code of a project you have.

When you ask Codex to do a task and finish it, will not apply the changes directly. It will show you what it has done with the records of everything executed, and you are the one who will have the final say to accept the result, request modifications or discard it. If you have connected GitHub, changes to a repository will arrive to you as a pull request to review.

In Xataka Basics | 64 free AI courses with Claude, ChatGPT, Gemini and Copilot created by your own companies