  We study a simple model of vector dark matter that couples to Standard Model
particles via magnetic dipole interactions. In this scenario, the cosmological
abundance arises through the freeze-in mechanism and depends on the dipole
coupling, the vector mass, and the reheat temperature. To ensure cosmological
metastability, the vector must be lighter than the fermions to which it
couples, but rare decays can still produce observable 3$\gamma$ final states;
two-body decays can also occur at one-loop with additional weak suppression,
but are subdominant if the vector couples mainly to light fermions. For
sufficiently heavy vectors, induced kinetic mixing with the photon can also
yield additional two body decays to lighter fermions and predict indirect
detection signals through final state radiation. We explore the implications of
couplings to various flavors of visible particles and emphasize leptophilic
dipoles involving electrons, muons, and taus, which offer the most promising
indirect detection signatures through 3$\gamma$, $e^+ e^- \gamma$, and $\mu^+
\mu^- \gamma$ decay channels. We also present constraints from current and past
telescopes, and sensitivity projections for future missions including
e-ASTROGAM and AMEGO.
