Detailed primary account of AGASA’s energy-determination method (lateral density profile calibrated to a Monte Carlo air-shower simulation) and the resulting >10-year energy spectrum from 10^14.5 to a few x10^20 eV, underpinning AGASA’s above-GZK flux claim. relevance_note: methods/primary-data paper for the AGASA flux measurement, needed to weigh how AGASA’s absolute energy scale (and resulting flux-above-LHC-equivalent count) compares with HiRes/Auger.