X releases For You timeline source code on GitHub

X has released the source code for its ‘For You’ timeline on GitHub under the Apache v2 license. According to Keith Coleman, X’s VP of Product, the release includes the core ranking code used to pull, rank, and assemble user feeds. The repository also contains the systems used to filter content that violates platform rules.

In addition to the open-source release, X is testing new tools to help users understand how algorithms affect their visibility. Through an ‘Under the Hood’ page, a selected test cohort of users can download their data as a JSON file to check for account labels, such as those indicating a ‘shadowban’—a practice where a platform deprioritizes a user's posts without official notification.

To access these testing tools, accounts must be at least one year old, have posted at least ten times in the last month, and be part of the random test group. While the JSON data may be difficult for non-technical users to interpret, the company suggests using large language models, such as Grok, to analyze the information using the GitHub documentation for guidance.