You can get tmux session persistence and multiplexing in Windows Terminal by running tmux inside WSL and setting the default shell to PowerShell. New panes and windows will then start pwsh.exe instead of a Linux shell. Here’s a minimal setup using small wrappers and the tmux -C attach trick to configure new sessions.

Why tmux under WSL with PowerShell?

Since tmux does not run natively on Windows, the standard approach is to use it through WSL. However, if you launch wsl tmux from Windows Terminal, all panes will default to your WSL shell. When working in a Windows directory, I prefer to use native PowerShell within the Windows environment.

To ensure every tmux pane runs PowerShell, configure tmux to use pwsh.exe as its default command. When you launch pwsh.exe from WSL within a Windows directory, it brings us back to the Windows environment.

Wrappers so you can call tmux from PowerShell

Put these in a directory on your PATH (e.g. ~/Documents/PowerShell/bin).

PowerShell — tmux.ps1:

wsl tmux $args

Cmd — tmux.cmd:

@echo off
wsl tmux %*

From PowerShell or Cmd you can then run tmux new, tmux attach, etc., and they all go to WSL’s tmux.

Creating PowerShell Sessions

The next piece is a script that creates a new session whose default command is pwsh.exe, or attaches if that session already exists. Example usage: tmux-pwsh dev or tmux-pwsh work.

The script sets the default command only for sessions it creates; it does not affect sessions started with a standard tmux new-session.

tmux-pwsh.ps1:

param(
    [Parameter(Mandatory=$true)]
    [string]$SessionName
)

$pwshCommand = "exec pwsh.exe -nologo"

# Check if session exists using exact name match
wsl tmux has-session -t "\=$SessionName" 2>$null

if ($LASTEXITCODE -ne 0) {
    wsl tmux new-session -d -s $SessionName $pwshCommand
    echo "set-option default-command `"$pwshCommand`"" | `
        wsl tmux -C attach -t "\=$SessionName" >$null
}
wsl tmux attach -t "\=$SessionName"

Note:

  1. The = prefix does an exact session name match and must be escaped when sending the command from PowerShell to WSL.
  2. The new session specifies command pwsh.exe via the command argument.
  3. Running wsl tmux set-option immediately after creating the session does not work because there’s a brief window where the session is not available for setting options. Instead, sending set-option via tmux -C attach reliably applies the setting.

After this, splitting panes and creating new windows in that session will all start pwsh.exe -nologo in Windows Terminal.

Summary

  • Use WSL for tmux and PowerShell as the default command by setting tmux’s default command to exec pwsh.exe -nologo.
  • tmux.ps1 / tmux.cmd — thin wrappers so tmux from Windows means wsl tmux.
  • tmux-pwsh.ps1 <name> — create (or attach to) a named session that uses PowerShell as the default command.

Once these are on your PATH, run e.g. tmux-pwsh dev from Windows Terminal to get a tmux session where every pane is PowerShell.