  In this work we present PRyMordial: A package dedicated to efficient
computations of observables in the Early Universe with the focus on the
cosmological era of Big Bang Nucleosynthesis (BBN). The code offers fast and
precise evaluation of BBN light-element abundances together with the effective
number of relativistic degrees of freedom, including non-instantaneous
decoupling effects. PRyMordial is suitable for state-of-the-art analyses in the
Standard Model as well as for general investigations into New Physics active
during BBN. After reviewing the physics implemented in PRyMordial, we provide a
short guide on how to use the code for applications in the Standard Model and
beyond. The package is written in Python, but more advanced users can
optionally take advantage of the open-source community for Julia. PRyMordial is
publicly available on GitHub.
