Codex for Windows: install, desktop app and sandbox setup

Codex for Windows comes in three forms: the ChatGPT desktop app (the Codex docs’ name for the app), the codex command line, and the IDE extension for VS Code. All three run natively on Windows 11, with a Windows sandbox that keeps the agent’s commands inside your project, or inside WSL2 with the Linux sandbox. Most people want the desktop app from the Microsoft Store, or the CLI from one PowerShell command.

The CLI in one line:

powershell -ExecutionPolicy ByPass -c "irm https://chatgpt.com/codex/install.ps1 | iex"

Open a new terminal, go to your project and run codex. Choose Sign in with ChatGPT.

Which Codex should I install?

They share one home folder on Windows, %USERPROFILE%\.codex, with your config.toml, sign-in and sessions.

How do I download the Codex desktop app on Windows?

The app is in the Microsoft Store. Install it from the Store page, or from a terminal:

winget install --id 9PLM9XGG6VKS -s msstore

Both routes go through the Store catalog. Open the app from the Start menu, sign in with your ChatGPT account, and add a project folder.

Install Git and the GitHub CLI too. The app needs Git for its review panel and gh for GitHub features:

winget install --id Git.Git
winget install --id GitHub.cli
gh auth login

Without the Microsoft Store. OpenAI publishes offline MSIX packages for managed machines, with a license file:

• https://persistent.oaistatic.com/codex-app-prod/ChatGPT-x64.msix
• https://persistent.oaistatic.com/codex-app-prod/ChatGPT-arm64.msix
• https://persistent.oaistatic.com/codex-app-prod/ChatGPT-License.xml

Rename the package to ChatGPT.msix, keep it next to the license, and install it from an elevated PowerShell:

Add-AppxProvisionedPackage -Online `
  -PackagePath .\ChatGPT.msix `
  -LicensePath .\ChatGPT-License.xml `
  -Regions all

This needs admin rights and provisions the app for every user on the machine. If it doesn’t appear, sign out and back in. The app still updates itself afterwards, from persistent.oaistatic.com.

How do I install the Codex CLI on Windows?

Pick one route and stick to it:

The PowerShell installer downloads from releases.openai.com and falls back to GitHub. If your network blocks the first, force GitHub:

$env:CODEX_INSTALLER_USE_RELEASES_OPENAI_COM='false'; irm https://chatgpt.com/codex/install.ps1 | iex

To pin a version, download the script and pass -Release:

Invoke-WebRequest -UseBasicParsing -Uri 'https://chatgpt.com/codex/install.ps1' -OutFile '.\codex-install.ps1'
powershell -ExecutionPolicy Bypass -File .\codex-install.ps1 -Release <version>

The single-exe trap: OpenAI’s deployment guide warns that copying only codex.exe isn’t a complete install. If the sandbox misbehaves after a manual copy, reinstall with the script or npm.

With npm, PowerShell can refuse to run the codex and npm launchers with “cannot be loaded because running scripts is disabled on this system”, so neither command starts. The fix the Codex docs give is Set-ExecutionPolicy -ExecutionPolicy RemoteSigned. Read Microsoft’s note on execution policies first; on a work machine, ask IT.

Check what you have with Get-Command codex and codex --version. Two installs on PATH, say npm and the script, is the usual reason an update “didn’t work”.

How do I sign in: ChatGPT plan or API key?

The Codex docs recommend the API key for CI and scripts. Some features may not be available with a key; the Codex pricing page lists which. codex login status shows which method is active.

Cached sign-ins live in %USERPROFILE%\.codex\auth.json or in Windows Credential Manager, set by cli_auth_credentials_store (file, keyring, auto or ephemeral) in config.toml. Treat auth.json like a password.

PowerShell or WSL?

Native is the default and the better choice for Windows projects. Choose WSL2 when your build expects Linux, when your work already lives there, or when the Windows sandbox won’t run on your machine. WSL1 is not supported since Codex 0.115.

CLI in WSL2:

wsl --install

Then, inside the Linux shell:

curl -fsSL https://chatgpt.com/codex/install.sh | sh
codex

Desktop app in WSL2: open Settings (codex://settings), switch Agent environment from Windows native to Windows Subsystem for Linux, and restart the app. The change doesn’t apply until you do.

VS Code with WSL: install the WSL extension (ms-vscode-remote.remote-wsl), run code . from the WSL shell in your project, and check that the status bar says WSL: <distro>.

Share one sign-in between Windows and WSL by pointing the WSL CLI at the Windows home folder. Add this to ~/.bashrc:

export CODEX_HOME=/mnt/c/Users/<windows-user>/.codex

The Codex WSL guide says to keep repositories in the Linux home folder, not under /mnt/c, for speed. The desktop app guide says projects on the Windows drive, opened as /mnt/<drive>/..., are more reliable, and that Git isn’t detected for projects opened through \\wsl$. Both are right for their surface: CLI in WSL, keep code in Linux; desktop app with a WSL agent, keep code on C:\.

How does the Windows sandbox work?

With the usual setup, Codex runs commands freely inside the project and asks before anything that leaves it. On Windows, three implementations enforce that:

Check your build with winver. Microsoft is still rolling MXC out, so a fully updated machine may not have it yet.

The desktop app prefers MXC on its own for consumer accounts. For the CLI, turn it on in %USERPROFILE%\.codex\config.toml:

[features]
prefer_mxc = true

Or pick an implementation directly:

[windows]
sandbox = "elevated"   # or "mxc", "unelevated"

Test it from your project folder (CLI 0.162.0 or later):

codex -c windows.sandbox=mxc sandbox --include-managed-config --permission-profile :workspace -- cmd.exe /d /c echo MXC_OK
$LASTEXITCODE

MXC_OK and 0 mean the sandbox works. Inside a session, /status shows your permissions and writable folders, and /debug-config shows whether a managed config overrides yours.

In the desktop app, the sandbox applies when Ask for approval is selected under the composer. Full access mode lets Codex act outside the project, and the docs warn this can lose data.

Older guides tell you to start Codex with --full-auto and change approvals with /approvals, but neither exists anymore, so those commands fail. Use /permissions in a session, or --approve-for-me to let an automatic reviewer handle approvals inside the sandbox. See YOLO mode for what each switch turns off.

Why does the Codex sandbox fail on Windows?

/setup-default-sandbox appears in the CLI only when Codex has fallen back to the restricted-token sandbox; it runs the elevated setup. To remove the legacy sandbox’s accounts and firewall rules, run codex sandbox uninstall as administrator.

The log is at %USERPROFILE%\.codex\.sandbox\sandbox.log. When you file a bug, include it with your Windows build and which implementation was active. Never share the .sandbox-secrets folder.

Why does Codex keep crashing on Windows?

Most reports are about the desktop app, not the CLI. The ones with open GitHub issues as of November 2026:

• The app crashes when it uses its built-in browser. Issue 32683 has 170+ comments. Avoid Browser Use tasks until it’s closed.
• “Not responding” on every launch. Issue 27809 traces it to VCPkgSrv.exe crashing.
• Hangs on the logo after a Windows update, or crashes right at start. Reported on several 25H2 builds. Update the app from the Store first.
• Crashes after adding a project with several root folders, then reopening the same state on every start. Until it is fixed, add projects one folder at a time.

The IDE extension has its own documented fix. If it stops responding, install the C++ build tools and the x64 Visual C++ Redistributable, then fully restart VS Code:

winget install --id Microsoft.VisualStudio.2022.BuildTools -e

Other Windows traps from the docs:

• The agent needs admin rights for a task. Start the app with Run as administrator; the agent inherits it. Do this only for that task.
• Git features missing. Install Git natively with winget install Git.Git, even if you have Git in WSL.
• Cmder is missing from the “Open” list. Right-click Cmder, choose Add to Start, then restart Codex.

Contenox

Contenox is a Windows desktop app that can use your ChatGPT subscription too: sign in with a device code, open a project folder, and the agent works there while you approve. Its rules are visible under Permissions, and on Windows a sandbox limits writes to the project folder; reads can’t be restricted there. See ChatGPT subscription and download it.

Related guides

• AI coding agents on Windows: which agents run natively and which need WSL
• Claude Code on Windows: the same setup for Claude Code
• Why does my coding agent keep asking for permission?: Codex’s network and folder prompts explained
• How to sandbox AI coding agents: when the built-in sandbox isn’t enough