  We test a model recently proposed for the persistent hard X-ray emission from
magnetars. In the model, hard X-rays are produced by a decelerating
electron-positron flow in the closed magnetosphere. The flow decelerates as it
radiates its energy away via resonant scattering of soft X-rays, then it
reaches the top of the magnetic loop and annihilates there. We test the model
against observations of three magnetars: 4U 0142+61, 1RXS J1708-4009, and 1E
1841-045. We find that the model successfully fits the observed phase-resolved
spectra. We derive constraints on the angle between the rotational and magnetic
axes of the neutron star, the object inclination to the line of sight, and the
size of the active twisted region filled with the plasma flow. Using the fit of
the hard X-ray component of the magnetar spectrum, we revisit the remaining
soft X-ray component. We find that it can be explained by a modified
two-temperature blackbody model. The hotter blackbody is consistent with a hot
spot covering 1-10% of the neutron star surface. Such a hot spot is expected at
the base of the magnetospheric e+- outflow, as some particles created in the
e+- discharge flow back and bombard the stellar surface.
