WSL2: Cannot paste image from Windows clipboard (missing PowerShell fallback)

Environment

• OS: Windows 11 + WSL2 (Ubuntu 22.04)
• Terminal: WezTerm
• Claude Code version: 2.1.90
• \TERM_PROGRAM\: WezTerm
• \WSL_DISTRO_NAME\: Ubuntu-22.04
• \WSL_INTEROP\: /run/WSL/344443_interop

Problem

Pasting images with \Ctrl+V\ in Claude Code does nothing on WSL2. The clipboard appears empty even after taking a Windows screenshot (Win+Shift+S).

Root Cause (traced through binary)

Claude Code's image paste logic (in \xvK()\) selects clipboard commands by platform:

• macOS → \osascript\ (works, system-native)
• Linux → \xclip -selection clipboard -t TARGETS -o\ or \wl-paste -l\
• Windows → \powershell Get-Clipboard -Format Image\

On WSL2, \process.platform\ returns \"linux"\, so it uses the Linux branch. But WSLg's clipboard bridge only syncs text formats — image data from the Windows clipboard is never passed through to the X11 clipboard. So even with \xclip\ installed, \checkImage\ finds nothing.

Verified:
\\\`bash

After taking a Windows screenshot:

$ xclip -selection clipboard -t TARGETS -o
TIMESTAMP
TARGETS
UTF8_STRING
TEXT

No image/png — WSLg dropped it

\\\`

The PowerShell code to read the Windows clipboard image already exists in the Claude Code binary for the \win32\ branch — it just never runs on WSL2.

Expected Fix

Detect WSL2 (via \WSL_INTEROP\, \WSLENV\, or \WSL_DISTRO_NAME\ env vars) and fall back to \powershell.exe\ when the Linux clipboard check finds no image.

Confirmed that \powershell.exe\ is callable from WSL2:
\\\`bash
$ powershell.exe -NoProfile -Command \
'$img = Get-Clipboard -Format Image; if ($img -ne $null) { "has image" } else { "no image" }'

Returns "no image" only because clipboard was empty at test time — the call itself works

\\\`

Reference Implementation

OpenAI Codex solved the exact same problem in openai/codex#5644:

1. Detect WSL via env vars (\WSL_INTEROP\ / \WSLENV\ / \WSL_DISTRO_NAME\)
2. On clipboard failure, call \powershell.exe -NoProfile -Command\ with:

\\\powershell
$img = Get-Clipboard -Format Image
if ($img -ne $null) {
$p = [System.IO.Path]::ChangeExtension([System.IO.Path]::GetTempFileName(), 'png')
$img.Save($p, [System.Drawing.Imaging.ImageFormat]::Png)
Write-Output $p
} else { exit 1 }
\\\

1. Map the returned Windows path (\C:\...\) to its WSL mount path (\/mnt/c/...\)

The fix is minimal — the PowerShell command already exists in Claude Code's \win32\ branch. It just needs a WSL detection check to route into it from the Linux path.