Kidney stones, which have high prevalence and recurrence rates, often cause severe oxidative damage and inflammation. The ultrasmall hydrodynamic diameter of nanoparticles is crucial for their enrichment in the kidneys to exert biological activity. However, integrating crystallization inhibition and therapeutic functions into a single ultrasmall nanoparticle is challenging. A novel ultrasmall iron (Fe)-gallic acid (Ga) metal-phenolic networks (Fe-Ga MPNs) is developed for treating calcium oxalate (CaOx) nephropathies. These MPNs can specifically adsorb on the high-energy (