Windows: Console windows flash when running Bash commands (missing windowsHide option)

Description

On Windows, every Bash tool call causes console windows (cmd.exe) to flash briefly on screen. This is disruptive to workflow and visually jarring.

Environment

• OS: Windows 10/11
• Claude Code version: v2.0.76
• Node.js: v22.19.0

Steps to Reproduce

1. Run Claude Code on Windows
2. Execute any Bash command (e.g., node --version)
3. Observe console window flashing

Root Cause

Claude Code's internal child_process.spawn() calls don't use windowsHide: true. This affects:

1. The Bash/shell spawn for running commands
2. Stop hook spawns (e.g., node stop-hook.js)

Attempted Workarounds (all failed)

• NODE_OPTIONS injection: Set NODE_OPTIONS=--require suppress-spawns.js to monkey-patch spawn - Claude Code appears to sanitize this environment variable
• PATH shims: Creating wrapper scripts would flash windows themselves
• VBScript wrappers: Can't handle stdin for hooks

Suggested Fix

Add windowsHide: true to spawn options when running on Windows:

spawn(command, args, {
    ...options,
    windowsHide: process.platform === 'win32'
});

This is a one-line fix that would eliminate the flashing entirely.

Additional Context

We successfully fixed window flashing in our own code (MCP server spawns) using windowsHide: true and the process.type = 'utility' trick to satisfy the Electron check in the MCP SDK. However, Claude Code's internal spawns remain unfixed and we have no way to patch them externally.

Impact

• Affects all Windows users
• Multiple windows flash per command (we counted ~5 per dev:start workflow)
• Significantly disrupts development workflow