Support for Stract

Stract (https://stract.com) is an open source search engine with its own index. One of its stand-out features are filters, called optics, which customize search results by removing or boosting certain sites.

It has an API, which means that support in Gugal can be added. Its API is currently free, but might become paid later.

This question comes after a poll I did on Mastodon for this feature got 2 votes in favor and none against. Since there weren't a lot of votes on that poll I'm also allowing voting on this issue for some time using reactions or replies.