  We considered a model for the prompt phase of Gamma-Ray Burst (GRB) emission
arising from a magnetized jet undergoing gradual energy dissipation due to
magnetic reconnection. The dissipated magnetic energy is translated to bulk
kinetic energy and to acceleration of particles. The energy in these particles
is released via synchrotron radiation as they gyrate around the strong magnetic
fields in the jet. At small radii, the optical depth is large, and the
radiation is reprocessed through Comptonization into a narrow, strongly peaked,
component. At larger distances the optical depth becomes small and radiation
escapes the jet with a non-thermal distribution. The obtained spectra typically
peak around $\approx 300$keV (as observed) and with spectral indices below and
above the peak that are, for a broad range of the model parameters, close to
the observed values. The small radius of dissipation causes the emission to
become self absorbed at a few keV and can sufficiently suppress the optical and
X-ray fluxes within the limits required by observations (Beniamini & Piran
2014).
