X open-sources its feed algorithm on January 20, 2026, built on Grok

On January 20, 2026, X open-sourced the core architecture of its feed-ranking algorithm, built on a Grok-based transformer model. The company outlined an end-to-end machine-learning system in Rust and Python and pledged four-week public updates with developer notes. The move coincides with stricter policies on crypto-linked engagement apps.