next-redux-saga-hydrate.js

import { HYDRATE } from 'next-redux-wrapper';

const initialState = {
  // initial state here ...
};

const projectsReducer = (state = initialState, action) => {
  switch (action.type) {
    // This will overwrite client state
    case HYDRATE: {
      return { ...action.payload.projectsReducer };
    }

    // reducer logic here ...

    default:
      return state;
  }
};

export default projectsReducer;