[Windows] Failed to spawn agent command: spawn with shell:false cannot run .cmd files

[sipoli007]

Description

When acpx uses Node.js child_process.spawn to launch subprocesses on Windows with shell: false, it fails to properly recognize and execute .cmd files like npx.cmd.

Current Code Pattern

spawn('npx.cmd', ['claude'], { shell: false, ... })

Problems on Windows

1. .cmd files require a shell: When shell: false, Node.js cannot directly execute .cmd files because they are not native executables - they require cmd.exe to interpret them.

2. Path with spaces not handled: The default Node.js path D:\Program Files\nodejs\npx.cmd contains spaces, which can cause additional issues when not properly quoted or handled.

3. Error behavior: The spawn call may fail with ENOENT (file not found) error.

Error Message

Failed to spawn agent command: D:\Program Files\nodejs\npx.cmd

Root Cause

The .cmd batch files on Windows are not directly executable - they need to be run through cmd.exe.

Recommended Solutions

Option 1: Use shell: true

spawn('npx.cmd', ['claude'], { shell: true })

Option 2: Explicitly use cmd.exe (Recommended)

spawn('cmd.exe', ['/c', 'npx', 'claude'], { shell: false })

Option 3: Use npx directly without .cmd extension

spawn('D:/Program Files/nodejs/npx', ['claude'])

Environment

• OS: Windows 10/11
• Node.js: v22.x
• acpx: 0.1.15

Expected Behavior

acpx should successfully spawn subprocesses on Windows without requiring users to manually configure shell execution.