According to cryptobriefing, X released the complete source code of its 'For You' recommendation algorithm on GitHub on January 20, 2026. Hosted in the xai-org/x-algorithm repository, the algorithm was rewritten using Rust and Python, replacing the old Scala code from 2023. The algorithm employs a multi-stage pipeline that first retrieves candidate posts, then uses the Phoenix Transformer model, based on xAI Grok technology, to predict and rank the probability of user interactions. Active interactions such as reposts and comments are weighted more heavily, while reports and blocks result in reduced weighting. X has become the first mainstream social media platform to publicly release the working code of its recommendation system, although key model weights and configuration parameters remain hidden. On August 13, a transparency tool was added to the repository, allowing users to view post tag statistics.