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

window:toast_notification(title, message, [url, [timeout_milliseconds]])

{{since('20210502-154244-3f7122cb')}}

Generates a desktop "toast notification" with the specified title and message.

An optional url parameter can be provided; clicking on the notification will open that URL.

An optional timeout parameter can be provided; if so, it specifies how long the notification will remain prominently displayed in milliseconds. To specify a timeout without specifying a url, set the url parameter to nil. The timeout you specify may not be respected by the system, particularly in X11/Wayland environments, and Windows will always use a fixed, unspecified, duration.

The notification will persist on screen until dismissed or clicked, or until its timeout duration elapses.

This example will display a notification whenever a window has its configuration reloaded. The notification should remain on-screen for approximately 4 seconds (4000 milliseconds), but may remain longer depending on the system.

It's not an ideal implementation because there may be multiple windows and thus multiple notifications:

local wezterm = require 'wezterm'

wezterm.on('window-config-reloaded', function(window, pane)
  window:toast_notification('wezterm', 'configuration reloaded!', nil, 4000)
end)

return {}