The TECHNO-CLS project aims to develop the technologies needed to design and realise novel crystal-based gamma-ray light sources operating from ~100 keV up to the GeV range. These sources rely on exposing oriented crystals (linear, bent and periodically bent) to ultra-relativistic charged-particle beams, giving access to new regimes of channeling radiation, crystalline synchrotron radiation and crystalline undulators. Building on successful FP7 and H2020 collaborations that demonstrated the crystalline undulator concept and produced and characterised periodically bent crystals, TECHNO-CLS establishes a high-risk, high-gain research programme that links fundamental radiation–matter physics with enabling technologies for future light sources. Within this international consortium, theoretical, computational, experimental and technological work are combined to describe the interaction of high-energy electron and positron beams with crystals at the atomistic level of detail required for device design. The University of Kent contributes to the theoretical and computational aspects of the project, in particular through quantum-chemical and multiscale modelling of radiation-driven processes in crystalline and molecular systems. The outcomes of TECHNO-CLS will support the development of next-generation gamma-ray light sources for applications across nuclear physics, condensed-matter science and the life sciences.