User:CategoryWatchlistBot

CategoryWatchlistBot is a bot operated by Bamyers99 that logs category and template additions and removals to/from wiki pages. The bot runs once an hour.

Specific categories and templates can be monitored using a watchlist. View a Sample Watchlist. A watchlist news feed is available to get automatic notifications of additions and removals. Category and template names can be matched exactly or partially. Additions and removals can be monitored individually or both at the same time. Complete page category removal can also be monitored.

A list of all of the recent category and template additions and removals is available here.

Supported wikis
Request additional wikis on the talk page.
 * Wikipedia Commons
 * English Wikipedia
 * Português Wikipedia (suspended, nobody is using)

Frequently asked questions

 * Why can't template included categories be searched?
 * The processing time required to run an old version of a page through the wikitext parser to get the categories is too great.


 * How are subcategories calculated?
 * A breadth-first search is performed until a maximum of 500 subcategories are found. The subcategories are recalculated once a week.

Program flow

 * 1) Get the recent changes list for the past hour.
 * 2) For each page that was changed, get the most recent version and the most recent version before the past hour.
 * 3) Extract the category and template names used in both versions.
 * 4) Compare the two versions and save the differences.

Source code

 * GitHub
 * Change log