This technology provides systems, methods, and compositions of miniature CRISPR-associated (Cas) nucleases to edit genes and control their activation and inhibition. A novel application of this technology is single vector homology directed repair (HDR), which can be used for CAR/TCR T cell engineering, hematopoietic stem cell (HSC) modification, and exon replacement for muscular dystrophy or cystic fibrosis. This technology also has applicability in the development of diagnostic tools, in addition to gene therapies. Therefore, these small CRISPR enzymes are of interest to companies in the field of gene editing.