BREAKING: X is open-sourcing the For You timeline and introducing a new level of transparency.

The released code will explain how posts are ranked and filtered, including:

• Core ranking systems • Model configurations • Timeline filters • Content labels that can affect a post's visibility

X is also launching an "Under the Hood" page that will allow eligible users to see whether visibility-limiting labels were applied to their accounts or posts, and download that data.

The pilot will initially include a randomized group of accounts that are at least one year old and posted 10+ times during the previous month. X also invited independent recommender-system experts to review and pressure-test the release.

This is a major step toward helping users understand how their reach is determined, whether the system is fair, and why certain content appears in their feeds.