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How-to4 min read

Codex Cloud: how it works, and when to use a shared space instead

Codex Cloud runs Codex tasks in OpenAI's cloud from published environments. How to set it up, what it can't reach, and when a shared Mirasim space fits better.

Members of a Mirasim cloud space: an owner, an admin and a collaborator, with what each role can doMembers of a Mirasim cloud space: an owner, an admin and a collaborator, with what each role can do

The short answer

Codex Cloud is OpenAI's way to run Codex coding tasks in the cloud. You prepare an environment from your GitHub repositories once, then start tasks from ChatGPT on the web, the desktop app, your phone or the Codex CLI. Each task gets its own workspace and keeps going while your computer is asleep, and you review the changes and open a pull request when you're ready.

Codex Cloud
You want to hand off tasks and review pull requests later
Codex Cloud
Your company is on ChatGPT Enterprise and wants shared, managed environments
Mirasim
You want Claude Code and other agents in the same cloud space as Codex
Mirasim
Several people want to steer one session together, live

How Codex Cloud works

  1. Create an environment

    In ChatGPT on the web or desktop: Work in › Cloud › Select environment › Create environment

  2. Let Codex prepare it

    Pick GitHub repositories; Codex installs dependencies and tests the setup

  3. Publish

    Review the setup and test results, then publish

  4. Start tasks

    Each task gets its own workspace; review, follow up, commit or open a PR

  • From the terminal: codex cloud opens a picker, codex cloud exec submits a task, codex cloud list shows recent ones, and codex apply brings a cloud task's diff into your local repository.
  • On your phone: open Codex in the ChatGPT app and pick a published environment.
  • Network: choose full or restricted public internet access, add network secrets for specific HTTPS services, and connect a VPN for private services.

Codex Cloud and a Mirasim team space

Codex CloudMirasim team space
What runsCodex, in OpenAI's cloud environmentThe Codex CLI itself, plus Claude Code, Kimi Code, DeepSeek Harness, OpenCode and five more agents
WhereA workspace per task, started from a published environmentA space we host (Linux or Mac); or your own computer or an SSH server
Working togetherEnterprise workspaces can share an environment; each person's tasks stay separateMembers join the space; several people send into the same session, each message signed
Code hostingGitHubGitHub and GitLab, each person as themselves
Where you use itChatGPT web, desktop app, phone, and the Codex CLIThe Mirasim desktop app, phone apps, or a browser
PayingYour ChatGPT planYour own accounts and keys, a key shared with the team, or Mirasim credit

From each product's documentation on November 8, 2026. For prices, see chatgpt.com/pricing and mirasim.ai/pricing.

Chapter 11 · Team spaces →

Questions

Is Codex Cloud the same as the Codex CLI?
No. The CLI runs on your computer; Codex Cloud runs tasks in OpenAI's cloud. The CLI can start and list cloud tasks with codex cloud.
Can teammates see my Codex Cloud task?
In an Enterprise workspace you can share an environment, but OpenAI's docs say access to the setup doesn't grant access to someone else's task. In a Mirasim team space, members work in the same sessions.
Can Mirasim run Codex Cloud?
No. Mirasim runs the Codex CLI, on your computer, an SSH server or a team space we host, which keeps running after you close your laptop.
Can a team share my ChatGPT plan in Mirasim?
A personal ChatGPT subscription is for its owner only, so a session your team shares runs on a shared key or space credit.

Article · Mirasim vs Cursor Cloud Agents → Cursor's cloud agents compared with a Mirasim team space.

Article · Claude Code on the web: how cloud sessions work, and when a shared space fits better → Claude Code's cloud sessions on the web, and how they compare.

Sources

Codex Cloud details were checked against OpenAI's documentation on November 8, 2026: learn.chatgpt.com/docs/cloud, /docs/environments/cloud-environments, /docs/environments/modes, /docs/mobile and /docs/developer-commands. Codex changes quickly, so check those pages for the latest.

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