Introduction Roboticists have long dreamed of generalist robots that can step out of the lab and perform useful tasks in unstructured, everyday settings. The challenge is generalization – can a robot handle a task in a brand-new environment with new objects, not just the scenarios it was trained on? The π0.5 model (pronounced “pi zero-point-five”) is a Vision-Language-Action (VLA) model proposed in April 2025 as a step toward this goal. It builds on an earlier π0 model and aims to endow r