Are peroxisomes part of the endomembrane system

No, peroxisomes are not considered part of the endomembrane system. Unlike organelles such as the endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles which are interconnected and part of a trafficking network, peroxisomes form independently either by budding from the ER or by division of existing peroxisomes. They lack direct vesicular transport connections with other endomembrane organelles, distinguishing their biogenesis and maintenance pathways.