  We report the Astrorivelatore Gamma ad Immagini LEggero (AGILE) observations
of solar flares, detected by the on board anticoincidence system in the 80-200
keV energy range, from 2007 May 1st to 2022 August 31st. In more than 15 yr,
AGILE detected 5003 X-ray, minute-lasting transients, compatible with a solar
origin. A cross-correlation of these transients with the Geostationary
Operational Environmental Satellites (GOES) official solar flare database
allowed to associate an intensity class (i.e., B, C, M, or X) to 3572 of them,
for which we investigated the main temporal and intensity parameters. The AGILE
data clearly revealed the solar activity covering the last stages of the 23rd
cycle, the whole 24th cycle, and the beginning of the current 25th cycle. In
order to compare our results with other space missions operating in the
high-energy range, we also analyzed the public lists of solar flares reported
by RHESSI and Fermi Gamma-ray Burst Monitor. This catalog reports 1424 events
not contained in the GOES official dataset, which, after statistical
comparisons, are compatible with low-intensity, short-duration solar flares.
  Besides providing a further dataset of solar flares detected in the hard
X-ray range, this study allowed to point out two main features: a longer
persistence of the decay phase in the high-energy regime, with respect to the
soft X-rays, and a tendency of the flare maximum to be reached earlier in the
soft X-rays with respect to the hard X-rays. Both these aspects support a
two-phase acceleration mechanism of electrons in the solar atmosphere.
