01What Is the Codex Mobile App?

The Codex mobile app is a new update to OpenAI's Codex that lets you control your AI coding agent from your phone. You can start tasks, review changes, and approve actions while the actual coding happens on your computer. The app works on both iOS and Android.

In this episode, Julian explains that the phone acts as a remote control. Your code stays on your laptop or desktop. The phone just streams what's happening, so you can see and approve things from anywhere.

This update is a big step toward making AI coding more flexible and hands-off.

02Main Features of the Codex Mobile App

The Codex mobile app brings several key features to your phone. You can do all of the following from the ChatGPT app:

  • Start new coding tasks from anywhere.
  • Continue old tasks you were working on.
  • View diffs, which are the changes the AI made to your code.
  • Review test results.
  • Approve or deny commands the agent wants to run.
  • Switch between different AI models.
  • Watch long-running jobs in real time.

One important detail is that your code never leaves your computer. Passwords and files stay safe. The phone only streams a view of the action, so you can approve or change things without being at your desk.

03How to Set Up the Codex Mobile App

Setting up the Codex mobile app is simple, according to Julian. Here are the steps he showed:

  1. Open the Codex app on your computer.
  2. Look for the QR code displayed on the screen.
  3. Open the ChatGPT app on your phone.
  4. Scan the QR code with your phone's camera.
  5. Wait for the connection to confirm.

That's it. No complex installation or configuration. Once connected, your phone can communicate directly with your Codex agent.

You can start using it right away, whether you're at home, on a train, or out for a walk.

04How to Use the Codex Mobile App in Daily Work

Julian walks through several real-life examples of using the Codex mobile app. These show how it fits into your routine:

  • Fixing bugs on the go: You get an alert about a bug while on a bus. You open the app, tell Codex to fix it, and approve actions from your phone. By the time you get home, it's done.
  • Running big refactors overnight: A refactor rewrites a large part of your code. You start it before bed. Codex works all night, occasionally asking for approval. You wake up, check your phone, approve, and go back to sleep.
  • Reviewing pull requests from anywhere: A pull request is when a teammate wants to add code. You can review the changes from your phone, even from bed or a coffee shop. Codex shows you what's different, and you decide.
  • Spinning up new ideas: You get an app idea at dinner. You open the app, tell Codex to start building, and by the time you get home, a prototype is waiting.

The phone is just the controller, not the computer. The real coding happens on your machine.

05Results and Comparisons From the Episode

This episode focuses on the impact of the update rather than specific test results. Julian compares the new Codex experience to the old way of coding with AI. Before, you had to sit at your desk, type a prompt, wait, check output, and repeat.

It was slow and tied you to your chair.

Now, you can start a task, walk away, and let the agent work. Julian also mentions the competition between OpenAI and Anthropic. Anthropic's Claude Code became popular because it could run for long periods.

This Codex update is OpenAI's response, aiming to match that capability while adding mobile control.

06Tips, Limits, and Mistakes to Avoid

Julian offers several tips and warnings. One key point is to remember that the phone does not do the coding. It is only a remote control.

Some people might worry that their code is on the phone or on OpenAI servers, but that is not the case. The code stays on your computer.

Another tip is to use the approval feature wisely. When the agent asks to run a command, you should look at it before tapping yes. You can also choose between different ways to fix a bug when the agent offers options.

A common mistake is to think you need to be a hardcore coder to use this. Julian says you don't need a computer science degree. You just need to know what you want to build and how to ask for it.

07Who Should Use the Codex Mobile App

The Codex mobile app is for anyone who uses AI coding agents and wants more freedom. It is especially useful for developers who work on the go or manage multiple projects. You can be on a train, at lunch, or walking your dog, and still keep your coding tasks moving.

Julian emphasizes that this update changes how we work. You become a manager of AI workers instead of a coder. You give the AI a job, walk away, and it does the work.

When it needs help, it pings your phone. This is a big shift that will affect how companies hire and build software.