A bot is a computer program that automatically retrieves or updates wiki pages when it is executed. In general, bots are used for repetitive maintenance tasks, whose volume and characteristics are too large to be performed manually by users.
Developing and executing bots is normally outside the role of normal users, requires programming experience and must be done in coordination with the wiki's admins.
By default, bot edits are hidden in Special:Recent changes.
Framework and interface for bot development
Bots do not access the wiki through the normal graphical user interface. MediaWiki has an API (Application Programming Interface) available for this purpose. An API is a protocol for standardised communication between two computer programs. Check Template:Mediawiki for more information.
To access a wiki through the API a bot must have a user account, which has been granted 'bot' permissions.
Template:Mediawiki provides a framework for the development of bots, which are commonly used to perform maintenance tasks such as adding a footer to some categorized pages add_text.py, adding some wikilinks (Template:Mediawiki), moving old contents of talk pages to subpages (Template:Mediawiki), editing categories (Template:Mediawiki), or managing templates (Template:Mediawiki).
The MassEditRegex extension
Extension:MassEditRegex provides an alternative way to perform mass edits using regular expressions, through a special page in the wiki. Only admins can normally use this extension.