Source counts of hard X‐ray AGNs contributing to the CXB shown for the band 13–80 keV and compared with the HEAO 1 A‐4 data point (Levine et al. 1984). We also show the extrapolation to the 13–80 keV band of the BeppoSAX HELLAS 5–10 keV counts on assuming different absorbing column densities: ﹩N_{\mathrm{H}\,}=10^{21}﹩ cm﹩^{-2}﹩ (short‐dashed line), 10²³ cm⁻² (long‐dashed line), 10^23.5 cm⁻² (dot‐dashed line), and 10²⁴ cm﹩^{-2}﹩ (dotted line).