Molecular dynamics (MD) simulations are a cornerstone of modern-day computational chemistry and biology, and in the last 40 years a range of general-purpose codes have been developed to make simulations more reproducible and accessible to the community . Although the preparation of typical biomacromolecular systems, e.g. proteins, lipid membranes or nucleic acids containing standard residues, has become extremely streamlined and automated , the corresponding topology files -containing a full description of the system's connectivity and energetics -can be unreadable and not amenable to simple manual manipulation. As a result, any non-automated departure from these standards, such as removing atoms or adding bonds, can become a painstakingly complex process, in particular for novice users not aware of nuances and caveats of these fixed file formats.