This module allows for having a configurable border position around windows; i.e., it can move the border to any cardinal direction.

To use this module, first import it into your configuration file:

import XMonad.Layout.SideBorderDecoration

You can now add the sideBorder combinator to your configuration:

main :: IO ()
main = xmonad
     $ …
     $ sideBorder mySideBorderConfig
     $ def { … }
 where
  mySideBorderConfig :: SideBorderConfig
  mySideBorderConfig = def
    { sbSide          = D
    , sbActiveColor   = "#ff0000"
    , sbInactiveColor = "#ffaaaa"
    , sbSize          = 5
    }

or, alternatively,

main :: IO ()
main = xmonad
     $ …
     $ sideBorder def{ sbSide = D, sbActiveColor = "#ff000", … }
     $ def { … }

See SideBorderConfig for the different size and colour options.

The following is a fully-functional, minimal configuration example:

import XMonad
import XMonad.Layout.SideBorderDecoration

main :: IO ()
main = xmonad $ sideBorder def $ def

This would result in the following border being displayed: