OpenAI has significantly revamped the 'Codex CLI' and introduced 'Codex Cloud,' which allows Codex to run on the cloud.

OpenAI's Codex CLI , a tool that allows you to inspect, edit, and run code from the terminal, has been revamped with several functional improvements.

Codex CLI just got a major refresh, with a new look and powerful new capabilities.

We're continuing to invest in Codex CLI for developers who live in the command line.

New full-screen interface, better readability, and ways to manage parallel work, all inside your terminal. pic.twitter.com/B4swb7DUkg

— OpenAI Developers (@OpenAIDevs) September 29, 2026

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https://learn.chatgpt.com/docs/environments/cloud-environments

At the ' OpenAI DevDay 2026 ' event held on September 29, 2026, OpenAI announced a major overhaul of the Codex CLI, revealing the addition of 'a new look and powerful new features.'

For example, older history is now loaded every time you scroll, and it can now be displayed beyond the device's scroll-back limit. The composer remains fixed and waiting for the next message input, so you don't need to scroll back to input even if you've scrolled through past history.

Older history loads as you scroll, beyond your terminal's scrollback limit.

Your composer stays pinned and ready for your next message, so you can explore long sessions without scrolling back to type. pic.twitter.com/GKw5id5npu

— OpenAI Developers (@OpenAIDevs) September 29, 2026

The `/agents` command now allows you to check currently running tasks and switch between them, while the `/fork` command allows you to run parallel sessions while maintaining the same context.

The Codex CLI now gives you a better way to manage parallel work.
Use /agents to see what's running, check progress, and jump between tasks.

Want to try another direction? /fork a conversation into a worktree with the same context and a separate checkout. pic.twitter.com/xRHhg7E3wn

— OpenAI Developers (@OpenAIDevs) September 29, 2026

You can also use the /voice command to give instructions using your own voice.

You can now talk to Codex in your terminal. And it talks back.

Use /voice to kick off work or talk through your next step, then jump into Agents to see everything moving. pic.twitter.com/qLnws7BAc6

— OpenAI Developers (@OpenAIDevs) September 29, 2026

In addition, several new features have been added, including the ability to analyze activity and usage, and new themes.

There's a lot more for builders packed into the Codex CLI update:

– /usage for activity and usage analytics

– New themes to choose from with /theme

– Support for managed worktrees

– Mermaid diagrams and LaTeX rendered directly in the terminal

– Collapsible diffs and tool… pic.twitter.com/nthJFwurCZ

— OpenAI Developers (@OpenAIDevs) September 29, 2026

At OpenAI DevDay 2026, they also announced ' Codex Cloud, ' a cloud environment for Codex.

You can finally close your laptop now and your agents will keep working.

Codex cloud environments are here.

Reusable environments mean less setup and faster starts, with your repo, dependencies, scripts, and settings already in place. pic.twitter.com/uW4jFb0QnV

— OpenAI Developers (@OpenAIDevs) September 29, 2026

Codex Cloud is a feature that checks GitHub to retrieve necessary information and builds a cloud environment. Once the environment is built, each task launched from it has its own dedicated virtual machine and continues to run even when the developer's computer is asleep. Changes that have not yet been sent to the connected GitHub repository are retained in the task, so you won't lose your changes even if you reopen the task later from your smartphone or browser. The dependency cache is also retained after background updates to keep the repository up to date.

Codex Cloud will be gradually rolled out to ChatGPT Plus and Pro subscribers, and will also be available in Business, Enterprise, Edu, and Healthcare workspaces.