This project is unmaintained, check out fof/formatting for a replacement!
s9e\mediaembed is a Flarum extension that automatically embeds third-party content in messages.
The most up-to-date list of supported sites is available in docs. The actual list of supported URLs depends on Flarum's Composer dependencies.
Install via Composer by running this command in your Flarum directory:
composer require s9e/flarum-ext-mediaembed:*