Redux-composers package introduces additional reducer composers besides combineReducers from redux, which enable to compose hierarchy in different ways. We introduce 3 additional composer reducers: chainReducers, mergeReducers and mapReducers. By definition, reducer composer is a function that turns multiple reducers into single reducer. Each type of composer manages state and reducers in different way, enabling you to build various hierarchies. Composers can be used in various use cases and combinations with other reducers.