So far, we’ve used Redux Toolkit and createAsyncThunk to handle API requests. But in larger applications, you may want more control over side effects, such as:

• Canceling requests when leaving a page
• Retrying failed requests
• Running parallel or sequential workflows
• Triggering multiple actions from one request
• Listening for specific UI or navigation events

This is where Redux-Saga shines.

In this article, we will integrate Redux-Saga to load Pokémon details from the Pokémon API when the user selects a Pokémon from the list.

🧠 What is Redux-Saga?

Redux-Saga is a middleware for Redux that uses generator functions (function*) to handle async workflows in a more declarative way.

Instead of doing:

dispatch(fetchPokemonDetails());

and hoping your async function handles everything…

Saga lets you describe how the side effect should work:

takeLatest("pokemon/fetchDetail", fetchPokemonDetailSaga);

This is more predictable and easier to test.

🏗 Step 1 — Install Redux-Saga

npm install redux-saga

🧱 Step 2 — Create Pokémon Detail Slice

src/features/pokemonDetail/pokemonDetailSlice.js

import { createSlice } from "@reduxjs/toolkit";

const pokemonDetailSlice = createSlice({
  name: "pokemonDetail",
  initialState: {
    data: null,
    loading: false,
    error: null,
  },
  reducers: {
    fetchPokemonDetail: (state) => {
      state.loading = true;
    },
    fetchPokemonDetailSuccess: (state, action) => {
      state.loading = false;
      state.data = action.payload;
      state.error = null;
    },
    fetchPokemonDetailFailure: (state) => {
      state.loading = false;
      state.error = "Failed to load Pokémon details.";
    },
  },
});

export const {
  fetchPokemonDetail,
  fetchPokemonDetailSuccess,
  fetchPokemonDetailFailure,
} = pokemonDetailSlice.actions;

export default pokemonDetailSlice.reducer;

Notice: This slice does not fetch data directly — the Saga will handle that.

🧙 Step 3 — Create Saga to Fetch Pokémon Details

src/features/pokemonDetail/pokemonDetailSaga.js

import { call, put, takeLatest } from "redux-saga/effects";
import {
  fetchPokemonDetail,
  fetchPokemonDetailSuccess,
  fetchPokemonDetailFailure,
} from "./pokemonDetailSlice";

function* handleFetchPokemonDetail(action) {
  try {
    const response = yield call(fetch, action.payload);
    const data = yield response.json();
    yield put(fetchPokemonDetailSuccess(data));
  } catch (error) {
    yield put(fetchPokemonDetailFailure());
  }
}

export function* pokemonDetailSaga() {
  yield takeLatest(fetchPokemonDetail.type, handleFetchPokemonDetail);
}

What’s Happening Here?

🏪 Step 4 — Add Saga Middleware to Store

Edit your store.js:

import { configureStore } from "@reduxjs/toolkit";
import createSagaMiddleware from "redux-saga";
import pokemonDetailReducer from "./features/pokemonDetail/pokemonDetailSlice";
import { pokemonDetailSaga } from "./features/pokemonDetail/pokemonDetailSaga";

const sagaMiddleware = createSagaMiddleware();

export const store = configureStore({
  reducer: {
    pokemonDetail: pokemonDetailReducer,
  },
  middleware: (getDefaultMiddleware) =>
    getDefaultMiddleware({ thunk: false }).concat(sagaMiddleware),
});

sagaMiddleware.run(pokemonDetailSaga);

We disable thunk because Saga will handle async logic.

🎨 Step 5 — Display Pokémon Detail in the UI

Example usage in PokemonDetail.jsx:

import { useDispatch, useSelector } from "react-redux";
import { fetchPokemonDetail } from "../features/pokemonDetail/pokemonDetailSlice";
import { useEffect } from "react";

export function PokemonDetail({ url }) {
  const dispatch = useDispatch();
  const { data, loading, error } = useSelector(
    (state) => state.pokemonDetail
  );

  useEffect(() => {
    dispatch(fetchPokemonDetail(url));
  }, [url, dispatch]);

  if (loading) return <p>Loading details...</p>;
  if (error) return <p style={{ color: "red" }}>{error}</p>;
  if (!data) return null;

  return (
    <div>
      <h2>{data.name.toUpperCase()}</h2>
      <img src={data.sprites.front_default} alt={data.name} />
    </div>
  );
}

✅ Result

You now have:

• A Redux slice to store Pokémon detail data
• A Redux-Saga that handles async fetching
• UI that loads smoothly and handles cancel/reload properly

When you click a Pokémon, its details load efficiently and predictably.

🧠 Why Saga is a Good Choice Here

Saga shines when your app grows and you need control.

🚀 Want the Next Step?

I can now create an advanced blog about:

Auto Refresh & Cancel API Requests with Redux-Saga (for example: refresh Pokémon detail every 10 seconds and stop when leaving the page)

Just tell me:

Do you want your explanation style to be:

1. Simple
2. Energetic YouTube style
3. Professional / Senior-Dev tone