Mass spectrometry (MS)-based proteomics analysis usually relies on database search. However, standard protein data-bases, such as NCBI-nr and Uniprot databases, don’t contain protein variants arising from SNPs that result in amino acid changes. Therefore, SAPshodt has been developed to introduce single amino acid polymorphism (SAP) information into an existing protein reference database on demand transmutator, enabling variant peptide detection in proteomics.