Researchers showcase an integrated photonic device with monocrystalline CsPbBr3 perovskite. Employing top-down etching approach, it introduces for micro lasers, beam splitters, X-couplers, Mach-Zehnder interferometers on perovskite films. This opens avenues for integrating perovskite semiconductors into optical chips, promising advancements in information and computing science.