API GetAddOnInfo — wowpedia

Get information about an AddOn.

name, title, notes, loadable, reason, security, newVersion = GetAddOnInfo(index or name)

Arguments

index: number - The index from 1 to GetNumAddOns(). Note that you cannot query Blizzard addons by index.
name: string - The name of the addon (as in TOC/folder filename), case insensitive.

Returns

name: string - The name of the AddOn (the folder name).
title: string - The title of the AddOn as listed in the .toc file (presumably this is the appropriate localized one).
notes: string - The notes about the AddOn from its .toc file (presumably this is the appropriate localized one).
loadable: boolean - Indicates if the AddOn is loaded or eligible to be loaded, true if it is, false if it is not.
reason: string - The reason why the AddOn cannot be loaded. This is nil if the addon is loadable, otherwise it contains a string token indicating the reason that can be localized by prepending "ADDON_". ("BANNED", "CORRUPT", "DEMAND_LOADED", "DISABLED", "INCOMPATIBLE", "INTERFACE_VERSION", "MISSING")
security: string - Indicates the security status of the AddOn. This is currently "INSECURE" for all user provided addons, "SECURE_PROTECTED" for guarded Blizzard addons, and "SECURE" for all other Blizzard AddOns.
newVersion: boolean - Not currently used.

Details

If the function is passed a string, name will always be the value passed, so check if reason equals "MISSING" to find out if an addon exists.
If the function is passed a number that is out of range, you will get an error message, specifically [<file name>]:<line number> AddOn index must be in the range of 1 to <GetNumAddOns()>

Patch changes

Patch 10.1.0 (2023-05-02): Added "SECURE_PROTECTED" security level for guarded addons.
Patch 6.0.2 (2014-10-14): Removed enabled return. The loadable return was changed from a flag to a boolean. Added newVersion return. The enabled state of an addon can now be queried with GetAddOnEnableState.