Shedding light on the $b\to s$ anomalies with a dark sector

The LHCb collaboration has recently reported on some anomalies in $b\to s$ transitions. In addition to discrepancies with the Standard Model (SM) predictions in some angular observables and branching ratios, an intriguing hint for lepton universality violation was found. Here we propose a simple model that extends the SM with a dark sector charged under an additional $U(1)$ gauge symmetry. The spontaneous breaking of this symmetry gives rise to a massive $Z^{\mathrm{\prime }}$ boson, which communicates the SM particles with a valid dark matter candidate, while solving the $b\to s$ anomalies with contributions to the relevant observables.