Physical Constants API
The NIST CODATA 2022 fundamental physical constants as an API — 355 quantities used throughout physics and engineering. Look up any constant by name or slug (e.g. speed of light in vacuum → 299792458 m/s, exact; Planck constant, elementary charge, Avogadro constant, Boltzmann constant, Newtonian constant of gravitation), search by keyword, or list them all. Each record carries the recommended value, the standard uncertainty, the SI unit and whether the value is exact (by definition since the 2019 SI redefinition). Ideal for scientific calculators, physics/engineering software, education and lab tooling.
api.oanor.com/constants-api
