Our recent adaptation of the original Seminario method 35 yields high quality parameters without relying on iterative fitting of the MM Hessian matrix, which avoids interdependency between force field parameters. In particular, the modified Seminario method has been shown to give parameters that are able to reproduce QM vibrational frequencies with an average error of 49 cm -1 for a test set of 70 molecules, which is slightly lower than that achieved by OPLS-AA (59 cm -1 ) and competitive with methods that rely on iterative fitting of the MM Hessian matrix. The second of the methods employed here is atoms-inmolecule (AIM) analysis, which provides a means to partition the QM molecular electron density amongst the constituent atoms, and hence assign atom-centered partial charges, even for systems comprising many thousands of atoms. Furthermore, the partitioned atomic electron densities can also be used in conjunction with the Tkatchenko-Scheffler (TS) relations to calculate all of the L-J parameters for a molecule. This method of using QM-derived non-bonded parameters has been shown to perform well in recreating liquid densities and thermodynamic properties when applied to a test set of 40 organic molecules. Collectively these methods form the basis of the QUantum mechanical BEspoke (QUBE) FF. Here, we present QUBEKit, a software toolkit designed to help users derive QUBE FF parameters in an intuitive and consistent way that minimizes parameter interdepen-dency. This first iteration combines previously benchmarked QM derivation methods for non-bonded, bond stretching, angle bending and torsion parameters, using the same functional form as the OPLS-AA FF, and is freely available to the community via our Github page (). Continuing a previous study that benchmarked the accuracy of the atoms-in-molecule non-bonded parameter derivation method, we re-derive parameters for a larger test set comprising over 100 small organic molecules using QUBEKit in a proof-of-concept workflow. We also expand upon the original non-bonded parameter derivation process by adding new fitting parameters that allow the derivation of FF terms for compounds containing bromine, as well as implementing a method for the derivation of off-center virtual site positions and charges directly from the QM electron density to model anisotropic electron densities. Combining these techniques we show through the use of the standard FF metrics described that the level of accuracy achievable with a QUBE FF is comparable to that of widely-used general transferable FFs. In this way, we provide the community with a tool for checking and refining parameter sets assigned through chemical similarity, and a starting point for FF improvements through optimization of the derivation protocols.