Coport computes covariant polarized radiation transfer in any spacetime. It is particularly useful for imaging black hole accretion systems. Written in Julia, it contains functions for handling the computation of all rays and a single ray, and deriving initial ray directions. Coport also has functions for interpolating GRMHD data, obtaining covariant emission, absorption, and Faraday rotation coefficients, and projecting the polarization tensor at the observer's screen, among other tasks.