An up-to-date scientific and applied problem of assessing the integrity of metallic structures in the context of the development of hydrogen energy is considered. The wide implementation of hydrogen power engineering, transport, metallurgy, chemical industry, and municipal services imposes increasingly strict requirements on the reliability of pipelines, high-pressure vessels, cylinders, compressors, and hydrogen refuelling station equipment. Current understanding of the mechanisms of hydrogen embrittlement of metals, in particular HELP, HEDE, and AIDE, which are considered as interrelated components of a multi-scale material degradation process, is summarized. Engineering integrity criteria which account for the influence of hydrogen are analyzed, including empirical indicators (RRA, Ni-equivalent, limiting values of strength and hardness), fracture toughness parameters (KIH, KISCC, J-integral, fracture energy Wс(CH)), as well as fatigue life and hydrogen-assisted cracking criteria. Special attention is paid to modern models for integrity assessment: diffusion models with trapping, coupled physicomechanical damage models, cohesive zone models, and phase-field approaches, as well as their role in developing simplified engineering methods for service life prediction of hydrogen infrastructure components. The main scientific and technical challenges and promising directions for further research, including the unification of integrity criteria, multi-scale integration of models, and the implementation of probabilistic and digital approaches to durability assessment, are formulated.