Manual:$wgConfigRegistry/en

Details
Registry of factory functions to create objects. MediaWiki core provides $global and $hash; extensions can create their own implementations of the interface if they wish, although it's typically not needed. MediaWiki core provides  and  ; extensions can create their own implementations of the interface if they wish, although it's typically not needed. The 'main' key must be set, and the value should be a valid callable. It's used for creating the main config object (available as the $mainconfig service). It's used for creating the main config object (available as the  service).