Created: 2008-06-01 20:24
Updated: 2018-03-24 16:21


Callout is a Firefox extension which delivers an API for web pages and Greasemonkey scripts to notify the user through the notification system of the OS. This would be Growl for Mac OS X users and Windows notifications for Windows users. The extension creates the callout JavaScript object which is usable by both unprivileged JavaScript code and Greasemonkey scripts.


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Callout supports Firefox 2.0+ on Windows and Linux and Firefox 3.0+ on Mac OS X. Mac OS X users will also need the Growl notification system. Greasemonkey is only required for userscript support.


Callout makes a callout JavaScript object available for all webpages and Greasemonkey scripts. The method creates a notification titled title and with the message message.

callout.notify(title, message, [options])

The available options are:

  • icon: with this you can specify an icon for the notification. This should be an URI for the icon. If unspecified the default Callout icon is used.
  • href: this specifies a target page to go to if the user clicks on the notification. This page will be opened in a new tab or window.


// Simple usage
callout.notify('Hello', 'World!');

// Specifying an icon
callout.notify('Hello World!', 'this is a ninja!',
               {icon: ''});

// Specifying a target page
callout.notify('I Can Scale', 'My blog',
               {href: ''});

Loudspy (defunct)

There is a more elaborate example in the examples directory for a Greasemonkey script which uses Callout. This script works worked on Digg spy and notified the user of each new digg displayed on the page.

Warning: while this could be useful for the digg addict it is a serious distraction from work. :)

This user script can also be installed from the following address:

Note: since the old Digg Spy have been retired this userscript is also defunct. Nevertheless it is a good way to see how a userscript which uses Callout could be written.


Author: László Bácsi

Hungarian blog post:

The original idea came from András Bártházi.


Copyright (c) 2008-2009 László Bácsi, released under the Mozilla Public License Version 1.1 (or alternatively GPL 2.0 or LGPL 2.1).

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