  We consider photon signals arising from the annihilation or decay of low-mass
(sub-GeV) dark matter which couples dominantly to quarks. In this scenario, the
branching fractions to the various kinematically accessible hadronic final
states can largely be determined from chiral perturbation theory. Several of
these final states yield striking spectral features in the sub-GeV photon
spectrum. New experiments, such as e-ASTROGAM and AMEGO, are in development to
improve sensitivity in this energy range, and we discuss their potential
sensitivity to this class of models.
