AddOn

What is an AddOn?

AddOns are generally self-contained User Interface (UI) modification components. However, some AddOns can be dependent on other AddOns to work, and some AddOns are actually collections of other AddOns. There is no size restriction on AddOns - you can actually implement a whole AddOn collection as one big Lua+XML chunk.

In plain English, it's just something you can put in your game folder that can (theoretically) improve your interaction with the World of Warcraft game (i.e. make it easier to play, or give you more information about what's going on in the game).

Often the name modification (or "mod" for short) is used interchangeably with AddOn. More specifically, mod is a third-party AddOn that alters or enhances some aspect of World of Warcraft's interface. Mods can perform a wide variety of tasks, including adding new buttons to the screen, altering the built-in player and party frames, and automating certain aspects of spell casting. In extreme cases, mods completely supplant the standard WoW interface, usually offering more advanced functionality.

Some mods are standalone, able to run without any additional software. Others are built on libraries such as Earth or Sea. Still others, such as Cosmos, are compilations of many individually-developed mods.

• See Hosted AddOn Pages for a list of AddOn pages on the wiki.
• For a good introduction and explanation, please see The Definitive AddOn and Macro FAQ.

How do I create an AddOn?

First of all, you need to create a new directory in Interface\AddOns. The name of this directory is kind of important, as it is what other AddOns use to refer to your AddOn (in dependencies). Therefore, using version numbers in your AddOn directory name can be a bad idea; you will run the risk of having other AddOns "break" when you change the version. This will probably lead to people either not depending on your AddOn or, worse, that they'll keep using an old version.

Major version numbers as part of AddOn directory names might work, though.

Within that folder you put your lua and xml files.

Note: The files must have the same name as the Addon folder, otherwise you will not see the Addon available within the game. So if your Addon is called 'testAddon', the folder would be named 'testAddon' and the files within it would be 'testAddon.lua' and 'testAddon.xml'.

What is this .toc file?

A functioning AddOn will need a file named <YourAddOnDirectoryName>.toc in "Interface\AddOns\YourAddOnDirectoryName\".

This file needs to have two things - an interface keyword with a correct interface number, and the name(s) of one or more files to load. However, Blizzard asks that you include at least these four lines:

## Interface: 11100
## Title: My Add On
## Notes: A short description of my addon
YourAddOnDirectoryName.xml

• Tip: Make sure you do not have any extra spaces at the end of the line with the filename specified. If you do, the extra space is taken as part of the filename and will cause your AddOn to silently fail to load.

The interface number can be seen in the WoW login screen, at the lower left. The number in the .toc file must match the current build or the add on will not be loaded/active. (Unless the user has explicitly told WoW to load out-of-date AddOns.)

Special case : Bindings.xml

If you include a Bindings.xml file, it does not have to be included in your .toc list of files to load - WoW loads this file automatically. This file is used to set key bindings specific to the AddOn.

What other keywords are there in the .toc file?

Please check out The TOC Format for a more detailed list.

See Also

• UI Beginners Guide has plenty of reference links
• The TOC Format
• Bindings.xml for creating key bindings
• UI FAQ/AddOns
• UI FAQ/AddOn Author Resources
• Troubleshooting a mod