  General relativistic radiative transfer calculations are essential for
comparing theoretical models of black hole accretion flows and jets with
observational data. In this work, we introduce Coport, a novel public code
specifically designed for covariant polarized ray-tracing radiative transfer
computations in any spacetime. Written in Julia, Coport includes an interface
for visualizing numerical results obtained from HARM, a publicly available
implementation of the general relativistic magnetohydrodynamics code. We
validate the precision of our code by comparing its outputs with the results
from a variety of established methodologies. This includes the verification
against analytical solutions, the validation through thin-disk assessments, and
the evaluation via thick-disk analyses. Notably, our code employs a methodology
that eliminates the need for separating the computations of spacetime
propagation and plasma propagation. Instead, it directly solves the coupled,
covariant, polarized radiative transfer equation in curved spacetime,
seamlessly integrating the effects of gravity with plasma influences. This
approach sets our code apart from the existing alternatives and enhances its
accuracy and efficiency.
