transset

transset [options] [value]

-a
    Activate mode: set the alpha value of the window under the cursor when clicked.

-c
    Use a color for alpha value calculation. (Not widely supported)

-d
    Use the default value for alpha if no value is provided.

-k
    Keep alpha value; change it only if initially set.

-m
    Specify the colormap ID to use.

-n
    Specify the window name to use when searching for a window.

-o
    Set the opacity directly (0-1).

-p
    Set opacity for all windows, not just the focused one.

-t
    Specify the window ID to target.

-x
    Set the target X position of windows to target (used with -y).

-y
    Set the target Y position of windows to target (used with -x).

[value]
    The opacity value to set. Can be an integer (0-255) or a float (0.0-1.0).

The transset command is a utility for manipulating the transparency properties of X Window System windows.
It allows users to set various transparency effects on windows, controlling their opacity and how they blend with the background.
Specifically, it targets the _NET_WM_WINDOW_OPACITY property, which is part of the Extended Window Manager Hints (EWMH) specification.
By modifying this property, transset can make windows partially or fully transparent.
The command typically works by identifying a target window, either through user interaction (clicking on the window) or by specifying its window ID.
Once the target window is identified, transset sets the opacity value based on the specified arguments.
It is a valuable tool for users who want to customize the appearance of their desktop and achieve specific visual effects. Some window managers do not fully support or honor the _NET_WM_WINDOW_OPACITY property.
Therefore, the behavior of transset can vary depending on the window manager in use.

The effectiveness of transset depends heavily on the window manager in use. Some window managers may not support or fully implement the necessary EWMH properties for transparency, causing the command to have no effect.

transset has been around as a small utility to leverage X Window System properties, enabling window transparency. The author wanted a simple, command-line way to manage window opacity without relying on the configurations of window managers. It has been improved over time and often finds its place in desktop environments that wish to provide customizable visual effects and require a fast and straightforward tool for managing the alpha values of windows.

xprop(1), xwininfo(1)