X For You Feed Algorithm is the open-sourced core recommendation system that powers the For You feed on X (the social network formerly known as Twitter), and it represents one of the first times a major social platform has published production-level ranking code for public review and experimentation. The repository contains the full pipeline that ingests user engagement and content candidate data, processes it through retrieval, hydration, filtering, scoring, and selection layers, and ultimately ranks posts to show what appears in a user’s feed. At its heart, the system uses a transformer-based model adapted from xAI’s Grok architecture to predict probabilities for various user actions (such as likes, replies, reposts, clicks, and negative signals), then combines those into a weighted final score that drives ranking.
Features
- Open-source recommendation system for the X “For You” feed
- Transformer-based scoring using engagement history
- Rust and Python production pipeline
- Multi-stage candidate retrieval and filtering
- Weighted multi-signal scoring integration
- Reference implementation for real-world ML ranking