ContextStream is a shared project memory tool designed for both people and AI agents working on coding projects. It captures what a project has learned and stores it as reusable memory that can be referenced in future AI coding sessions. ContextStream benchmarks competitively against other memory systems, achieving a 90.0% score on the LongMemEval-S benchmark, placing it within statistical parity of top-ranked systems like Zep. It is built to improve continuity and context retention across AI-assisted development workflows.