Overview
OpenAI Codex is an agent product from OpenAI for software engineering, with the official website at openai.com/codex/. On September 29, 2026, at DevDay 2026, OpenAI released reusable cloud environments (Codex Cloud environments). After developers connect a GitHub repository, Codex analyzes the codebase to identify the runtime, dependency package versions, and toolchain, and generates two configurations: an installation script and a startup skill. Users can converse with Codex to adjust and test them, and after confirmation, publish them as a snapshot; thereafter, every new task starts from that snapshot, with dependencies preinstalled, so there is no need to repeat the installation process. Each task runs in an independent cloud workspace. After the laptop lid is closed, the task continues in the cloud. Task status can be retained for 7 days from the last activity, during which it can be resumed from the web, desktop, phone, or terminal (codex cloud command), and uncommitted changes are also retained. The CLI was also refreshed at the same time. A code review interface was added to the ChatGPT desktop app. GitHub review is now generally available, and GitLab merge requests are in preview.
Key Features
- Reusable Cloud Environments: After developers connect a GitHub repository, Codex analyzes the codebase to identify the runtime, dependency package versions, and toolchain, and generates two configurations: an installation script and a startup skill. Users can converse with Codex to adjust and test them, and after confirmation, publish them as a snapshot; thereafter, every new task starts from that snapshot, with dependencies preinstalled, so there is no need to repeat the installation process.
- Independent Cloud Workspaces and Cross-Device Resumption: Each task runs in an independent cloud workspace. After the laptop lid is closed, the task continues in the cloud. Task status can be retained for 7 days from the last activity, during which it can be resumed from the web, desktop, phone, or terminal (codex cloud command), and uncommitted changes are also retained.
- Cloud Virtual Machine Specifications Divided by Plan: Plus and Edu Plus have 2 vCPU, 8 GiB memory, and 8 GiB disk. Pro, Business, and Enterprise have 4 vCPU, 16 GiB memory, and 32 GiB disk; Plus users also have a five-hour usage quota window shared by local and cloud tasks.
- Security and Network Controls: Network secrets cover the HTTPS services that tasks can access, and the environment itself limits the network destinations that Codex can reach.
- CLI Refresh and Code Review Interface: The CLI supports starting and controlling tasks by voice, adds an /agents view for centrally viewing parallel tasks, allows editing prompts, resuming sessions, and using worktrees, and switches to a terminal interface better suited for long sessions. These changes apply to all plans; the ChatGPT desktop app adds a code review interface that displays the Pull Request description, changed files, comments, and checks, allowing users to ask Codex about a specific change before submitting feedback to GitHub or GitLab; GitHub review is now generally available, and GitLab merge requests are in preview. After automatic review is enabled, Codex completes the first round of review in the cloud, and this path does not require a separate cloud environment.
Use Cases
- After connecting a GitHub repository, use reusable cloud environments to automatically analyze the codebase and generate installation script and startup skill configurations, reducing repeated installation processes.
- Execute coding tasks in an independent cloud workspace. After the laptop lid is closed, the task continues running, and it can be resumed across the web, desktop, phone, or terminal.
- Use the ChatGPT desktop app code review interface to view the Pull Request description, changed files, comments, and checks, and ask Codex before submitting feedback.
- After enabling automatic review, Codex completes the first round of review in the cloud, applicable to GitHub review and GitLab merge request preview.
- Use the CLI /agents view to centrally view parallel tasks, edit prompts, resume sessions, and use worktrees.
Pros
- Reusable cloud environments support starting new tasks from a snapshot, with dependencies preinstalled, so there is no need to repeat the installation process.
- Tasks run in independent cloud workspaces. After the laptop lid is closed, they continue in the cloud, and status can be retained for 7 days from the last activity.
- Supports resuming tasks from the web, desktop, phone, or terminal (codex cloud command), and uncommitted changes are also retained.
- Cloud virtual machine specifications are divided by plan. Plus and Edu Plus have 2 vCPU, 8 GiB memory, and 8 GiB disk. Pro, Business, and Enterprise have 4 vCPU, 16 GiB memory, and 32 GiB disk.
- Network secrets cover the HTTPS services that tasks can access, and the environment itself limits the network destinations that Codex can reach.
- The CLI supports starting and controlling tasks by voice, adds an /agents view for centrally viewing parallel tasks, and switches to a terminal interface better suited for long sessions.
Pricing
Available plans are Plus, Pro, Business, Healthcare, Education, and Enterprise; users with only an API key do not use the cloud environment feature. The virtual machine specifications for cloud tasks are divided by plan: Plus and Edu Plus have 2 vCPU, 8 GiB memory, and 8 GiB disk. Pro, Business, and Enterprise have 4 vCPU, 16 GiB memory, and 32 GiB disk; Plus users also have a five-hour usage quota window shared by local and cloud tasks. Specific prices are subject to the official website.
Summary
OpenAI Codex is an agent product from OpenAI for software engineering. On September 29, 2026, at DevDay 2026, it released reusable cloud environments, supporting independent cloud workspaces, cross-device resumption, code review, and parallel task management. Computer use and browser use are not currently supported in cloud environments, GitLab support is still in beta, self-hosted GitHub Enterprise Server is not supported, changes within tasks are not written back to the published environment, container caches are rebuilt from snapshots after being full for 12 hours, and local AGENTS.md and Personal Skills are not synced to cloud tasks.
Version History
- At DevDay 2026 OpenAI introduced reusable Codex cloud environments, with tasks running in isolated cloud workspaces and resumable across devices (2026-09-29):
- OpenAI launches the new Codex Cloud, Agents API opens preview and supports computer use. (2026-09-29):