Fetching Data with createAsyncThunk

What You Are Building

You will fetch data from an API using Redux Toolkit.

Creating an Async Action

Redux Toolkit provides createAsyncThunk to handle async logic.

import { createAsyncThunk } from '@reduxjs/toolkit';

export const fetchPosts = createAsyncThunk(
  'posts/fetchPosts',
  async () => {
    const response = await fetch('https://jsonplaceholder.typicode.com/posts');
    return response.json();
  }
);

Connecting to the Slice

Handle the async action inside your slice:

import { createSlice } from '@reduxjs/toolkit';
import { fetchPosts } from './postsThunk';

const postsSlice = createSlice({
  name: 'posts',
  initialState: {
    items: [],
    status: 'idle',
    error: null
  },
  reducers: {},
  extraReducers: (builder) => {
    builder
      .addCase(fetchPosts.pending, (state) => {
        state.status = 'loading';
      })
      .addCase(fetchPosts.fulfilled, (state, action) => {
        state.status = 'succeeded';
        state.items = action.payload;
      })
      .addCase(fetchPosts.rejected, (state, action) => {
        state.status = 'failed';
        state.error = action.error.message;
      });
  }
});

export default postsSlice.reducer;

createAsyncThunk lets you handle async logic in a structured way. It automatically tracks loading, success, and error states.