The same as an OS with a UI. Discoverability, fewer actions per activity, easier navigation, faster to learn/lower skill floor, etc. Some highlights:

1. Much better multi-agent orchestration. The app supervises many agents, with different project views and built-in git worktrees, so agents can work on isolated copies of the same repo. It's easy to jump between tasks and see changes. I recall OpenAI wrote that CLI was not designed around this style of work.

2. The app combines multiple terminals, file previews, PR-review workflows, SSH connections, an integrated browser, and page annotations. For front-end stuff, Codex can run the app in Codex for mockups/prototypes, then iterate inside the app. IMHO I think this is a much faster, more intuitive flow.

3. For long-running and recurring agent workflows, I think they're much easier to manage in the app. You get automations, review queues, persistent conversation context, future schedules, and auto resume for longer running tasks. E.g. CI failure summaries, issue triage, and release briefs.

You can do some of the above, to some degree, with varying levels of success in the CLI, but I think it's miles ahead in the app.

You get GUI niceties: a nice presentation of the output like inline markdown rendering including tables and images in a nice font. Input supports drag & drop, and I can actually navigate the input field the way I am used to (pointing and clicking, using keyboard shortcuts to jump to beginning of words / sentences). Not sure what the most modern CLIs support, but for me just the ergonomics of a GUI text field alone are superior.

It's easier to use for most people. I don't think CLI and GUI programs target the same audience.

I'm not ready to try this yet, since after some recent experiences[1] I've decided not to be at the cutting edge of new tools and models for a few weeks or months.

However, from the screenshots and description, I expect that you would have these advantages:

- History. Currently, if you type into the CLI (TUI) your intention and requests are captured in some transcripts, but not in conversational turns. If you want the history of what you typed into the cli/tui you would have to datamine it from transcripts. By contrast, on the screenshots you can see it is a simple conversation that's saved and easy to return to.

- Multiplatform. As per the announcement "Use Codex across ChatGPT, your editor, and the terminal", meaning that you could open the ChatGPT app on your phone and continue to interact with this. While this might not matter to you if you exclusively code while sitting in front of your computer, still, it helps you be able to stay on top of things if you are on mobile.

- Background tasks and autonomous work. It says you can schedule it to do things in the background (issue triage, alert monitoring). At the moment, it would only do this if you've asked either codex or another agent to build a harness for it that does so. (i.e. you could ask Claude to build a harness that calls Codex on some schedule or interval.)

These all seem pretty good and I look forward to starting to use it once it's been more battle-tested.

[1] notably, on the Anthropic side the Opus 5 regressions - I had to downgrade to Opus 4.8 as I found Opus 5 was unreliable. I currently use Opus 4.8 and Codex Sol 5.6.