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Lucas Santos
Lucas Santos
19,315 Points

Webpack dev server with ExpressJs

Ok so I have a very simple app with create-react-app. Now I'm using ExpressJS to handle API calls that I am making with the $.ajax() method inside of my react app within the componentWillMount() method.

So all the React front end has is a simple form with 1 input field and submit like so:

import React, { Component } from 'react';
import $ from 'jquery';
import './App.css';

class App extends Component {


      $('form').on('submit', function(e) {

          url: '/api',
          type: 'post',
          data: $('form').serialize(),
          dataType: 'json',
          success: function(data) {
            console.log('successful ajax request made!');


  render() {
    return (
      <div className="App">
        <form method="POST">
          <input type="text" name="title" />
          <input id="submit" type="submit" />

export default App;

Now my express route look like this:

var express = require("express");
var router = express.Router();

router.post("/api", function(req, res, next){

module.exports = router;


When running create-react-app with npm start it goes to localhost:3000 do to the Webpack local dev server and when I fire off my app.js in my server directory with node server/app.js is goes to localhost:3001 because they cannot run in the same port.

Because of this I cannot make proper API calls without getting an error showing that the POST request has failed.

So now the golden question is how can I make API calls from a local server on 2 different ports?

If you need any more info about my code i'd be more than happy to post it. Help is greatly appreciated, thank you!

1 Answer

You need to enable CORS to do this.

See this answer to a similar question on Stack Overflow, specifically the Express part.