{"openapi":"3.1.0","info":{"title":"Nuclear Physics API","version":"1.0.0","description":"Nuclear-physics maths as an API, computed locally and deterministically. The binding-energy endpoint computes a nucleus's mass defect, Δm = Z·m_H + N·m_n − M_atom, and its binding energy E = Δm·c² (1 u = 931.494 MeV) and binding energy per nucleon, from the proton and neutron counts and the measured atomic mass. The semf endpoint estimates the binding energy from the semi-empirical (Bethe-Weizsäcker) mass formula, breaking it into the volume, surface, Coulomb, asymmetry and pairing terms, from just the mass number and proton number. The q-value endpoint computes the energy released or absorbed in a nuclear reaction from the masses of the reactants and products, Q = (Σm_reactants − Σm_products)·c², classifying it as exothermic (fusion of light nuclei or fission of heavy ones) or endothermic. Masses are in atomic mass units and energies in MeV and joules. Everything is computed locally and deterministically, so it is instant and private. Ideal for physics-education, nuclear-engineering, astrophysics and science app developers, reactor and reaction tools, and STEM teaching. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. 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