Boxes.dev vs Codex

At a glance

As of October 2, 2026. This page compares boxes.dev with Codex Cloud, where OpenAI runs each Codex task on its own virtual machine, using the reusable cloud environments OpenAI introduced on September 29.

What the cloud machine starts from

Both start each task from a saved setup: Codex Cloud from an environment that Codex prepares from your GitHub repositories, and boxes.dev from a copy of a machine where your app already runs.

To create a Codex Cloud environment, you choose GitHub repositories, and Codex inspects them, installs their dependencies and tools, and tests the setup with you, asking for any access or values it needs. It records an install script and a start skill, which tells the agent how to start your services and check that they're ready. When you publish the environment, OpenAI saves its prepared files, and each new task runs on its own virtual machine started from them. To change the setup, you edit the environment with Codex and publish it again. Cloud tasks count toward your ChatGPT plan's usage allowance, with no separate charge for the machine.

Boxes.dev first sets up your full development environment on a cloud machine called the Template box, with the tools, databases, services, and data your app needs, so an agent can run the app and test its changes end to end. A setup agent can port the environment from your laptop, including the files, local data, agent settings, and skills you choose to upload, or build it from a GitHub repository. Boxes.dev then saves the Template box as a snapshot, and every task runs on its own devbox, a full, isolated copy of that machine. A maintenance script can keep the Template box current as your code changes, running on a schedule or when files such as a lockfile change, and each successful run saves a new snapshot.

You'd never let an engineer ship code they hadn't run, and a full environment holds the agent to the same standard. On a boxes.dev devbox, the agent runs your app and tests its changes in the browser as it builds, and it reproduces bugs in the real app to find the root cause instead of guessing from the code, so it writes better code and makes fewer mistakes. It can also take screenshots and record video for you to review, so you can hand it most repetitive manual testing.

What's kept between tasks

A boxes.dev devbox keeps its running programs through sleep and stays until you delete it, and a Codex Cloud task keeps its files for up to seven days after you last use it.

Each Codex Cloud task keeps its own files, including uncommitted changes and installed tools, so you can reopen it from the web, the ChatGPT mobile app, or the desktop app and continue. OpenAI's docs say a task's saved state can be recovered for up to seven days after you last start a turn or resume it. New tasks start from the published environment, and OpenAI refreshes its repositories in the background.

A boxes.dev devbox sleeps when nobody is using it, and an agent that is still working keeps it awake. Sleep keeps the machine's files and memory, so dev servers, databases, and terminal sessions resume where they left off when it wakes. You can come back the next day to the same files, branches, and data.

Working in the machine

In Codex Cloud, Codex runs the commands on the task's machine, and on boxes.dev, you can also work in the devbox yourself.

In a cloud task, you describe the goal, and Codex edits files, runs commands, and checks its work. You can then review the changed files and test results, ask for follow-up changes, and commit or open a pull request. The desktop app's integrated terminal works in projects on your computer.

On boxes.dev, you can open a terminal on the devbox, edit its files, and run your app alongside the agent, with the tools listed under What comes with every boxes.dev devbox, over SSH, or in VS Code or a JetBrains IDE with dvb ide.

Reaching the running app

On boxes.dev, you and the agent can both use the app running on a devbox, and the ChatGPT desktop app previews apps running on your computer.

The ChatGPT desktop app's built-in browser shows you and Codex web apps running on your computer, and you can comment on the page for Codex to address. OpenAI's cloud environment docs list browser and computer use as not yet supported in Codex Cloud.

Each boxes.dev devbox runs a browser that you and the agent share, so you can watch the agent test the app, click through it yourself, or comment on page elements to show the agent what to change. Ports forwards the app to the same localhost port on your laptop, a public link shares a devbox's running app with anyone, and a Project URL gives your project one stable public address that you can point at any devbox, which suits OAuth callbacks and webhooks.

Working with your team

Both bring agents into Slack, and boxes.dev also lets teammates you allow send follow-ups to your conversation and start work in your project, with your access.

In ChatGPT workspaces where an admin turns on Cloud delegation, mentioning @ChatGPT in Slack or Microsoft Teams can hand repository work to a Codex Cloud task, using an environment shared with the workspace. The task runs with your account, and ChatGPT posts the result in the thread. Your later requests in that thread can continue the task, and a request from someone else may start a separate task with their account. You can also share a cloud environment with your workspace so colleagues can start their own tasks from the same setup, without access to each other's tasks. In the ChatGPT desktop app for macOS, you can share a read-only snapshot of a local Codex thread by link.

Each boxes.dev devbox belongs to one person and works with their access, such as their GitHub login and cloud credentials. Anyone who can prompt its agent could act with that access, so in the app, teammates get read-only access to your work. You can share a thread as a link, and a team admin can let teammates read every thread that isn't marked private and browse each other's projects in a Team workbench. Teammates can't send prompts, open your terminal, or control your devbox.

In Slack, mentioning @boxes.dev in a thread starts Codex or Claude Code on a new devbox, and later mentions in that thread send follow-ups to the same conversation. By default, only you can start work in your project from Slack or follow up on it. If you allow teammates, they can also start work there with @boxes.dev @YourName and send follow-ups, and their requests run with your access and usage. Boxes.dev sends you a DM with links to each task a teammate starts, and commits can link to the thread that produced them.

What comes with every boxes.dev devbox

The boxes.dev desktop app opens the same set of tools for whichever devbox you select:

• Terminal, with tabs that keep running after you close the app.
• Files, a file browser and editor with search across the workspace.
• Git/Review, for branch history and diffs, where comments on changed lines go to the agent together as one message.
• Browser, the browser on the devbox that you and the agent share.
• Ports, for the forwarding, .localhost addresses, and public links described above.
• Activity, which shows the processes using the machine's CPU and memory.

AWS, Tailscale, and the MCP servers and Codex plugins you add for the project reach every devbox, and agents can leave each other notes in a shared /project folder. You can branch a conversation onto a new devbox that starts with the current files, including uncommitted work.

Where Codex shines

• One command from your terminal. codex cloud exec submits a task to a cloud environment, and codex apply brings a cloud chat's latest diff into your local repository.
• Automatic pull request reviews. Codex can review every new GitHub pull request, flag only high-priority issues, and follow review rules from AGENTS.md.
• Credentials kept out of cloud tasks. Programs in a task see a placeholder for each network secret, and a proxy adds the real value only to requests for the services you allow.
• Codex Security. A security agent finds, confirms, and helps fix vulnerabilities, from the desktop app, the terminal, an SDK, or connected GitHub repositories.

Pricing

As of October 2026.

A box-hour is one default devbox awake for an hour, and sleeping devboxes don't use any. On Starter, 40 box-hours works out to about two hours of devbox time each working day, and Pro's 250 to about twelve, spread across as many as ten devboxes at once. Your ChatGPT plan covers Codex's usage on boxes.dev, and the boxes.dev plan covers the machines. See Plans, seats, and box-hours.

OpenAI's pricing page says that weekly limits may also apply to the plan's usage allowance, and that Business costs $20 per user each month when billed annually. See Codex pricing.

Using both

We recommend using both. Codex is a great agent, and boxes.dev runs the real Codex CLI on every devbox with your ChatGPT subscription, so your AGENTS.md, skills, and settings work the same way in both places. You can keep Codex's automatic reviews on your pull requests and Codex Cloud for quick tasks from your phone, and use boxes.dev for tasks that need your full environment, a terminal, or the running app.

Frequently asked questions

Is boxes.dev affiliated with OpenAI?

No. Boxes.dev is an independent product and isn't affiliated with or endorsed by OpenAI.

Can I use my ChatGPT plan with boxes.dev?

Yes. Sign in with ChatGPT to connect Codex, or use an API key. Codex's usage on boxes.dev counts toward your ChatGPT plan, and boxes.dev charges only for machine time. See Connect Codex and Claude.

How does a Codex Cloud environment compare with a Template box?

Both save a prepared setup that each new task starts from. A Codex Cloud environment holds the GitHub repositories, dependencies, and tools that Codex set up and tested with you, and each task keeps its files for up to seven days after you last use it. A boxes.dev Template box is a full cloud machine where your app already runs, a maintenance script can keep it current, and each devbox copied from it stays until you delete it, with its running programs resuming when it wakes from sleep.

Do AGENTS.md, skills, and MCP servers work?

Yes. Codex on a devbox reads your repository's AGENTS.md, and project setup can copy agent settings, skills, and MCP definitions from your computer. Plugins that Codex syncs to your account work on devboxes too.

Sources

• Codex: Codex Cloud, cloud environments, Codex Cloud (Legacy), Codex CLI commands, GitHub code review, ChatGPT in Slack, Linear, integrated terminal, browser, sharing threads, subagents, Codex Security, and pricing.
• Boxes.dev: How boxes.dev works, Update your Template box and snapshots, Startup, teardown, and maintenance, Sleep, wake, and recover a devbox, Review a page with your agent, Preview your app, Project URLs, Shared project storage, Use the agent's terminal view, Install agent plugins, Organize and share threads, Team access and roles, Commit, push, and open a pull request, Install and use the CLI, Work from Slack, Work from Linear, Use boxes.dev on your phone, and Plans, seats, and box-hours.