Manual:$wgExtensionDirectory

Server URLs and file paths: $wgExtensionDirectory
The file system path to the extensions directory.
Introduced in version:	1.25.0 (Gerrit change 209216; git #cf2678e2)
Removed in version:	still in use
Allowed values:	(relative path)
Default value:	null (1.38+) "{$IP }/extensions" (1.25-1.37)
Other settings: Alphabetical | By function

Details

The file system path to the extensions directory (relative path). This controls where MediaWiki will look for extensions on the server itself.

This is set to "{$IP}/extensions" by Setup.php before loading local settings.

See also

• $IP
• $wgExtensionAssetsPath – the URL for extensions
• $wgStyleDirectory – filesystem path for skins