Classical off-shell currents

We consider tree-level off-shell currents of two massive particles and $n$ massless bosons in the classical limit, which can be fused into limit $n+2$ scattering amplitudes. show that dressing up current with coherent wave-functions associated leads to recently proposed Worldline Quantum Field Theory (WQFT) path integral. The thus constructed encode solutions equations motion so they applied contexts where is relevant, including hard thermal loops. give several examples these scalar, gauge gravitational theories.