  We present a new 1-D multi-physics simulation code with use cases intended
for, but not limited to, hydrodynamic escapeproblems of planetary atmospheres
and planetary accretion models. Our formulation treats an arbitrary number of
species asseparated hydrodynamic fields, couples them via friction laws, allows
for a multi-band flux-limited radiation transport, and tracksionization fronts
in high-energy irradiation bands. Besides coupling various known numerical
solution techniques together, weimprove on the numerical stability of deep
hydrostatic atmospheres by using a well-balanced scheme, hence preventing
unphysicaldriving of atmospheric in- or outflow. We demonstrate the correct
physical behaviour of the individual code modules and presenta few simple, new
applications, such as a proof-of-concept simulations of combined core-powered
mass-loss and UV-drivenatmospheric escape, along with a fully time-dependent
core-collapse giant planet simulation. The multi-species nature of thecode
opens up the area of exploring simulations that are agnostic towards the
dominant atmospheric species and can lead toimplementations of advanced
planetary evolution schemes.
