Enables mouse click passthrough on any Godot window on Windows - clicks pass through to whatever application is underneath, regardless of the window's visual style or transparency.

Built for desktop overlay and widget apps where the Godot window sits on top of the desktop, but must never intercept mouse input.

Why not Godot's built-in passthrough? DisplayServer.window_set_mouse_passthrough(polygon) defines a hit region within a Godot window - it cannot make clicks pass through to other applications underneath. This extension sets Win32 flags directly on the window's HWND to achieve true system-level passthrough.

Installation

1. Copy the windows_mouse_passthrough/ folder into your project's addons/ directory.
2. Go to Project → Project Settings → Plugins and enable Windows Mouse Passthrough.

Usage

func _ready() -> void:
    if Engine.has_singleton("MousePassthrough"):
        Engine.get_singleton("MousePassthrough").set_passthrough(
            get_window().get_window_id(), true
        )

The Engine.has_singleton guard keeps the script cross-platform safe. The extension is silently skipped on Linux and macOS.

API

MousePassthrough.set_passthrough(window_id: int, enabled: bool) -> void

Requirements

• Godot 4.3+
• Windows only