wezterm/docs/config/lua/window/current_event.md

window:current_event()

Since: 20220807-113146-c2fee766

Returns the current event. For now only implemented for mouse events.

This example prints the delta scroll value when you scroll up with your mouse wheel while holding CTRL:

local wezterm = require 'wezterm'

return {
  mouse_bindings = {
    {
      event = { Down = { streak = 1, button = { WheelUp = 1 } } },
      mods = 'CTRL',
      action = wezterm.action_callback(function(window, pane)
        -- note that you want `WheelDown` for a `WheelDown` event
        local delta = window:current_event().Down.button.WheelUp
        wezterm.log_info('delta is: ' .. delta)
      end),
    },
  },
}