Middleware Order

Middleware Order Overview

Middleware Order lets you work with Redux in a way that stays clear, repeatable, and easy to scale. Instead of ad-hoc steps, you follow a pattern that other developers recognise immediately.

The key is to keep middleware order focused and predictable. Start from the minimal example here, then add only the complexity your situation actually needs.

import { createListenerMiddleware } from '@reduxjs/toolkit';
import { increment } from './counterSlice';

export const listener = createListenerMiddleware();

listener.startListening({
  actionCreator: increment,
  effect: async (action, api) => {
    console.log('incremented', api.getState());
  },
});

Listener middleware reacts to dispatched actions to run side effects, replacing many custom thunks.

Middleware Order Example

const slice = createSlice({ name, initialState, reducers });
const store = configureStore({ reducer: { key: slice.reducer } });
// dispatch(slice.actions.something())

• Start from a minimal Middleware Order example and grow it only as needed.
• Keep things explicit so Middleware Order behaves the same for everyone on the team.
• Name things clearly so teammates understand your Middleware Order at a glance.
• Verify Middleware Order works as expected before relying on it in important work.

Redux Cheatsheet

Quick Redux Toolkit reference related to middleware order.

How Middleware Order Works in Redux

Middleware Order follows Redux's predictable data flow: components dispatch actions, reducers compute the next state from the previous state and the action, and subscribed components re-render.

Listener middleware reacts to dispatched actions to run side effects, replacing many custom thunks.

• State lives in a single, read-only store.
• Actions are the only way to describe a change.
• Reducers are pure functions that return the next state.
• Redux Toolkit removes most boilerplate with slices and thunks.

Practical Guidance for Middleware Order

In modern apps, middleware order should use Redux Toolkit rather than hand-written Redux. Keep state minimal, colocate logic in slices, and use RTK Query for server data.

Common Mistakes

• Skipping edge cases and error handling when using middleware order.
• Not verifying the result of middleware order before moving on.
• Over-complicating middleware order before you actually need the extra flexibility.
• Ignoring documentation, which makes middleware order hard for the next person to follow.

Key Takeaways

• Middleware Order is a core part of working effectively with Redux.
• Start small and keep middleware order focused on a single goal.
• Apply consistent patterns so middleware order scales across your project.
• Practise and document middleware order to keep your workflow maintainable.