Introduction

wsl-shadow reports when your interactive WSL shell and an AI agent on the same distro resolve node / npm / bun to different programs. It can propose fixes. It only writes when you type apply.

What it measures

Four shell views:

View	How it launches	What that shell reads
interactive	your terminal	~/.bashrc, ~/.profile if login
login	wsl.exe bash -lc, MCP "command": "wsl"	~/.profile (unless bash_profile / bash_login)
exec	wsl.exe -e sh -c, bash -c, spawn	nothing
here	the process running wsl-shadow	inherited PATH

WSL appends the Windows PATH. nvm and fnm usually load from ~/.bashrc. Agent shells often never read that file, so they get /mnt/c/.../nodejs/npm and a Windows prefix.

Status codes

Status	Meaning
ok	every measured view resolves to Linux, same version
shadow	a Linux build exists, and a view gets Windows
windows-only	a view gets Windows, and no Linux build exists
unreachable	a Linux build exists, and a view finds nothing
drift	every view is Linux, but versions disagree
missing	nowhere
unmeasured	that view could not be run; the tool does not guess
expected-windows	Windows build you marked expected (cursor / code by default, or --expect-windows)

Exit codes

• 0: every measured tool is fine
• 1: shadow / windows-only / unreachable / drift / invisible npm global bin / bad MCP under --mcp
• 2: a --require tool is missing

--mcp is read-only.

Measured output

WSL2 Ubuntu + nvm; Node also on Windows. Paths anonymized.

$ wsl-shadow --view=interactive,login,exec

unreachable  node
  interactive  /home/alex/.nvm/.../bin/node
  login        (not found)  <- fails
  exec         (not found)  <- fails

shadow       npm
  interactive  /home/alex/.nvm/.../bin/npm
  login        /mnt/c/.../nodejs/npm  <- fails
  exec         /mnt/c/.../nodejs/npm  <- fails