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+# Feed handler plugins

+

+!!! warning

+

+    Unless you have a strong need for these plugins, using them is not recommended. If

+    you do use them, at least don't enable them for all feeds.

+

+Some plugins utilize global per-feed content hooks which either modify fetched

+feed XML data (i.e. fixing broken XML) or even generate it entirely, for tt-rss

+to process, for websites that don't actually provide RSS feeds.

+

+While having this ability available for plugins is valuable there are several

+downsides:

+

+1. This entirely bypasses rate-limiting and article duplicate checking done

+   during normal feed update process. A badly written plugin using

+   <code>HOOK_FETCH_FEED</code> may cause your tt-rss feed to keep updating

+   feeds indefinitely, processing all articles every time, causing unnecessary

+   CPU load on your server.

+

+2. If you have full text content plugins enabled, this may cause excessive load

+   on origin server, because your tt-rss instance is going to scrape site

+   content for every provided article on every feed update.

+

+This may result in your tt-rss instance being banned by origin servers for

+causing excessive load and/or your VDS being suspended for suspected bad

+behavior.

+

+Additionally, tt-rss being blacklisted by feed publishers may negatively affect

+other users.