Concepts in PECOS are organized around the following namespaces:

circuits Circuits of different abstraction levels.
qeccs Represent QEC protocols.
error_gens Used to specify error models and generate errors.
simulators Simulate states and operations.
circuit_runners Coordinate gates of circuits and error_gens with a simulator.
decoders Produce recovery operations given syndromes.
tools Tools for studying and evaluating QEC protocols.
misc A catch all namespace.

Classes and functions available in these namespaces are described in the following: