  In this paper, we extend the resource theory of magic to the channel case by
considering completely stabilizer preserving operations (CSPOs) as free. We
introduce and characterize the set of CSPO preserving and completely CSPO
preserving superchannels. We quantify the magic of quantum channels by
extending the generalized robustness and the min relative entropy of magic from
the state to the channel domain and show that they bound the single-shot
dynamical magic cost and distillation. We also provide analytical conditions
for qubit interconversion under CSPOs and show that it is a linear programming
feasibility problem and hence can be efficiently solved. Lastly, we give a
classical simulation algorithm whose runtime is related to the generalized
robustness of magic for channels. Our algorithm depends on some pre-defined
precision, and if there is no bound on the desired precision then it achieves a
constant runtime.
