Coalescence is one of the main models used to describe the formation of light (anti)nuclei. It is based on the hypothesis that nucleons close in phase space can coalesce and form a nucleus. Coalescence has been successfully tested in hadronic collisions at colliders, from small (pp collisions) to large systems (A-A collisions). However, in Monte Carlo simulations (anti)nuclear production is not described by event generators. A possible solution is given by the implementation of coalescence afterburners, which can describe nuclear production on an event-by-event basis. This idea would find application in astroparticle studies, allowing for the description of (anti)nuclear fluxes in cosmic rays, which are crucial for indirect Dark Matter searches. In this work, the implementation of an event-by-event coalescence afterburner based on a state-of-the-art Wigner approach is discussed. The results here shown are obtained with the EPOS3 event generator and compared to the measurements performed in pp collisions at the LHC. In particular, the role of the emitting source in the coalescence process is discussed, comparing the results obtained using the direct measurement of the source size with the semi-classical traces implemented in EPOS3.