The Biomolecule Toolkit is supports a set of web services dedicated to support biopharmaceutical development. The toolkit enables the editing of chemical monomers and biological macromolecules by their HELM notation. With the HELM language, scientists are able to describe both structural and sequence data of macromolecules in one string. Furthermore, the toolkit provides an editable and clean inventory for biological assets and entitiesdiverse set of biological modalities such as peptides, oligonucleotides, proteins, antibodies, antibody drug conjugates, nanoparticle conjugates, including those containing non-natural or chemically modified residues and chemical decorations. Any of the above may be represented with full, partial, or no chemical structure information or added annotations. All other biological assets such as cell lines, plasmids, pooled samples, and clones are represented by their relevant metadata and annotations.