Using npx-create-react-app

Using bundlr with npx create-react-app

Bundlr is fully compatible with React, however, if you’re using npx create-react-app to create your project, you will need to do some additional configuration and installation. This guide details how to create a new React project and add Bundlr support, if you already have a React project open, free to skip down a few steps.

Create a new directory for your project, cd into it, and create your React project:

mkdir bundlr-react
cd bundlr-react
npx create-react-app .

Install the Bundlr library and ethers (for interacting with the blockchain):

npm install @bundlr-network/client ethers

There are currently two versions of ethers.js in use, if you're using the v5 release, change you App.js file to:

import { providers } from "ethers";
import { WebBundlr } from "@bundlr-network/client";
function App() {
	const initialiseBundlr = async () => {
		await window.ethereum.enable();
		const provider = new providers.Web3Provider(window.ethereum);
		await provider._ready();
		const bundlr = new WebBundlr("https://node1.bundlr.network", "matic", provider);
		await bundlr.ready();
		return bundlr; // done!
	return <div className="App">Bundlr Test</div>;
export default App;

If you're using the v6 beta version, the API has changed and you'll need to use the following code instead.

import { ethers } from "ethers";
import { WebBundlr } from "@bundlr-network/client";
// This code has been updated for ethers.js v6
// https://docs.ethers.org/v6-beta/getting-started/
function App() {
	const initialiseBundlr = async () => {
		// Connect to the MetaMask EIP-1193 object.
		// provider used for writing to the blockchain
		const provider = new ethers.BrowserProvider(window.ethereum);
		// signer used for reading from the blockchain
		const signer = await provider.getSigner();
		// link the signer to the provider
		provider.getSigner = () => signer;
		// create the WebBundlr object
		const bundlr = new WebBundlr("https://node1.bundlr.network", "matic", provider);
		await bundlr.ready();
		console.log("bundlr=", bundlr);
		return bundlr; // done
	return (
		<div className="App">
			<button type="button" onClick={initialiseBundlr}>
				Initialize Bundlr
export default App;

Viewing that page, you'll get a bunch of errors saying BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.

To fix this you'll need to include NodeJS polyfills which are no longer included by default.

Install first react-app-rewired, a package that allows for editing of the webpack config file to fix polyfill issue. Then install the missing dependencies.

npm install react-app-rewired
npm install --save-dev crypto-browserify stream-browserify assert stream-http https-browserify os-browserify url buffer process
npm install browserify-zlib path-browserify path

At the root level of your project, create a new file called config-overrides.js and paste the following in:

const webpack = require("webpack");
module.exports = function override(config) {
   const fallback = config.resolve.fallback || {};
   Object.assign(fallback, {
       crypto: require.resolve("crypto-browserify"),
       stream: require.resolve("stream-browserify"),
       assert: require.resolve("assert"),
       http: require.resolve("stream-http"),
       https: require.resolve("https-browserify"),
       os: require.resolve("os-browserify"),
       url: require.resolve("url"),
       zlib: require.resolve("browserify-zlib"),
   config.resolve.fallback = fallback;
   config.plugins = (config.plugins || []).concat([
       new webpack.ProvidePlugin({
           process: "process/browser",
           Buffer: ["buffer", "Buffer"],
   return config;

Override package.json to include the new webpack configuration. Look for this code block

 "scripts": {
   "start": "react-scripts start",
   "build": "react-scripts build",
   "test": "react-scripts test",
   "eject": "react-scripts eject"

and replace it with this block:

"scripts": {
   "start": "react-app-rewired start",
   "build": "react-app-rewired build",
   "test": "react-app-rewired test",
   "eject": "react-scripts eject"

Quit out of the React server and restart it with npm run start you should be good to go.

Working with Aptos

Aptos's export structure occasionally breaks webpack's ESM loader. If you're working with Aptos, you may need the following extra steps:

Modify your config-overrides.js file to include:

externals: {
	aptos: "aptos"

Change: import Bundlr from '@bundlr-network/client';

To: `import Bundlr from '@bundlr-network/client/build/cjs/web/bundlr';