  We study ultra-violet completions for d = 6 four-fermion operators in the
standard model effective field theory (SMEFT), focusing on models that contain
cold dark matter candidates. Via a diagrammatic method, we generate
systematically lists of possible UV completions, with the aim of providing sets
of models, which are complete under certain, well specified assumptions. Within
these lists of models we rediscover many known DM models, as diverse as
R-parity conserving supersymmetry or the scotogenic neutrino mass model. Our
lists, however, also contain many new constructions, which have not been
studied in the literature so far. We also briefly discuss how our DM models
could be constrained by reinterpretations of LHC searches and the prospects for
HL-LHC and future lepton colliders.
