Currently, custom scripts are supported in: AdGuard for Windows, AdGuard for Android and AdGuard for Mac (Mac version does not yet allow you to add your own custom scripts).
These userscripts come directly from AdGuard developers and we can guarantee that they will be effective and safe. Keep in mind that whenever you download a userscript from an unknown source you expose yourself to a risk. Some scripts can be harmful to your computer. Always get new scripts only from sources you trust 100%. Further are some examples of popular sites with scripts.
AdGuard Assistant - This extension lets you manage the filtering process right from the page.
AdGuard Extra - an extension that blocks advertising in difficult cases when the usual filter-based approach is not enough.
Userscripts are mostly created by enthusiasts, that is why you need to be careful when installing a new one. But nevertheless, there is a great variety of interesting scripts that can really make the use of some websites more convenient.
Here we will describe some of the most popular userscript catalogs.
Userstyles.org is a catalog of user styles, but it allows you to load them as userscripts. Thus, any user style can be installed via AdGuard. Be careful if you decide to install an unpopular script - there's a risk it might be harmful.
OpenUserJS.org is an open source userscript catalog written in nodeJS. It doesn't have moderation so stay alert to any suspicious scripts.
If you like the idea of personifying your browser with the help of userscripts, and you have any questions, you can ask them on one of these websites: