[WSL] Bind Alt+V to chat:imagePaste in addition to Ctrl+V for parity with Windows-native build

Summary

Two separate issues conspire to break image paste in Claude Code under WSL when it is launched from common Windows terminals. This report focuses on the first; the second is already tracked at #25935 and both must be fixed for a complete solution.

A) Platform-dependent defaults. Claude Code's default chat:imagePaste differs by build:

• Windows native: Alt+V
• Linux / WSL: Ctrl+V

When Claude Code runs inside WSL, several Windows terminals (Warp for Windows, PowerShell console host) capture Ctrl+V at the host level, so the TUI never receives it. Alt+V does reach the TUI under those terminals, but it is not bound to chat:imagePaste on Linux/WSL, so users cannot paste at all.

B) Related MIME handling (#25935). Even once the keybinding reaches the handler in WSL, the Linux-side clipboard check only accepts image/png, while Windows screenshot tools (Snipping Tool, Win+Shift+S) publish image/bmp via WSLg — causing "no image" errors even with the keybinding corrected. Fixing (A) alone is insufficient for WSL users on Windows.

Proposal (this issue)

Detect the WSL environment (e.g. WSL_DISTRO_NAME, /proc/sys/kernel/osrelease containing microsoft, or WSL_INTEROP) and add alt+v to the default chat:imagePaste bindings alongside ctrl+v. This provides parity with the Windows-native build and gives users a fallback key when the host terminal intercepts one of the two.

{ "ctrl+v": "chat:imagePaste", "alt+v": "chat:imagePaste" }

End-to-end workaround (validated)

Users today can fully restore WSL image paste with the following steps:

1. Move Warp's "Alternate terminal paste" off Ctrl+V. See https://github.com/warpdotdev/Warp/issues/7069#issuecomment-4277676645 for details.
2. Explicitly bind both ctrl+v and alt+v to chat:imagePaste in ~/.claude/keybindings.json under WSL — and, if a Windows-native build is also used, in C:\Users\<you>\.claude\keybindings.json as well. The proposal in this issue would make this step redundant.
3. Install a BMP → PNG clipboard converter to work around #25935 until Claude Code accepts image/bmp on Linux. A validated watcher (ImageMagick + wl-clipboard + xclip, polling at 300 ms since WSLg's Weston compositor does not support wl-paste --watch) is included in the Warp comment linked above.
4. Restart Claude Code on both sides.

Environment

• Claude Code CLI v2.1.114
• WSL2 Ubuntu 24.04 on Windows 11
• Reproduced with Warp for Windows and PowerShell (Windows console host). Community reports indicate WezTerm and Windows Terminal deliver the keypress to the child TUI, though this was not personally verified.