1import React, { useState, useEffect } from "react";
2import socketIOClient from "socket.io-client";
3const ENDPOINT = "http://127.0.0.1:4001";
4
5function App() {
6  const [response, setResponse] = useState("");
7
8  useEffect(() => {
9    const socket = socketIOClient(ENDPOINT);
10    socket.on("FromAPI", data => {
11      setResponse(data);
12    });
13  }, []);
14
15  return (
16    <p>
17      It's <time dateTime={response}>{response}</time>
18    </p>
19  );
20}
21
22export default App;

1connect to the socket server on component mount with useEffect
2save each new incoming message in the component's state.
3
4function App() {
5  const [response, setResponse] = useState("");
6
7  useEffect(() => {
8    const socket = socketIOClient(ENDPOINT);
9    socket.on("FromAPI", data => {
10      setResponse(data);
11    });
12  }, []);
13
14  return (
15    <p>
16      It's <time dateTime={response}>{response}</time>
17    </p>
18  );
19}

1npm install socket.io