Two Codex accounts, on Windows.

How does Codex decide which account you're on?

The Codex CLI doesn't keep a login per window. It keeps one login per folder: CODEX_HOME, which is %USERPROFILE%\.codex on Windows unless you set it. That folder holds auth.json (the login), config.toml (settings, including MCP servers) and your session history. One folder, one account.

The ChatGPT desktop app from the Microsoft Store (its package is OpenAI.Codex) uses the same %USERPROFILE%\.codex for its Codex data, so by default codex in a terminal and Codex in the app share one login. ChatGPT's built-in account switcher doesn't change that: it works on chatgpt.com and doesn't touch the CLI's login (more on the switcher).

If you installed the CLI yourself (for example with npm install -g @openai/codex), codex is on your PATH. The Store app also ships its own codex.exe; this finds it:

Join-Path (Get-AppxPackage OpenAI.Codex).InstallLocation 'app\resources\codex.exe'

How do you set up a second account in PowerShell?

1. Create a folder for the second account. Codex won't create it for you.

   New-Item -ItemType Directory -Force "$HOME\.codex-work" | Out-Null

2. Point CODEX_HOME at it and start Codex.

   $env:CODEX_HOME = "$HOME\.codex-work"
   codex

   Sign in with the second account when asked. You do this once per folder.
3. Use both. Every codex started from that window now uses .codex-work. Open a new PowerShell window and plain codex is back on your first account. Both can run at the same time.

To check where a window stands: $env:CODEX_HOME prints the folder (empty means the default), and codex login status answers Logged in using ChatGPT or Not logged in.

How do you make it one word?

Add a function to your PowerShell profile (notepad $PROFILE; create the file if it doesn't exist):

function codex-work {
    $previous = $env:CODEX_HOME
    $env:CODEX_HOME = "$HOME\.codex-work"
    try { codex @args } finally { $env:CODEX_HOME = $previous }
}

codex-work runs Codex in the work account and then puts the window back the way it was, so a later plain codex in the same window still uses your first account. Add one function per account.

Windows Terminal: add a profile per account and set its Command line to:

powershell.exe -NoExit -Command "$env:CODEX_HOME = Join-Path $HOME '.codex-work'; codex"

Name it something like “Codex (work)” and give it its own tab color, so you can see which account a tab uses.

cmd: use the quoted form of set, so no stray space ends up in the value:

mkdir "%USERPROFILE%\.codex-work"
set "CODEX_HOME=%USERPROFILE%\.codex-work"
codex

What should you watch out for?

Forgot to create the folder? Codex stops with Error loading configuration: CODEX_HOME points to "C:\\Users\\you\\.codex-work", but that path does not exist. Create it and try again.

What to copy: config.toml if you want the same settings in both (Copy-Item "$HOME\.codex\config.toml" "$HOME\.codex-work\"). Not auth.json, which is the login. Leave each folder's history where it is.

We make Sessions Pro for Codex.