---
title: FAQ
date: 2022-02-16T00:00:00+10:00
weight: 21
---

# FAQ

Frequently Asked Questions for developers using js-waku:

### 1. Why should I build a frontend only webapp (no NodeJS backend)?

Waku enables dApp to add communication, e.g. interaction between users, in a fully decentralized manner.
A webapp that uses NodeJS as a backend implies that a party runs said NodeJS software in a centralized infrastructure.

Despite using Waku & Ethereum, such webapp cannot become decentralized.

By building a frontend only webapp, that entirely runs in the browser, one can distribute the frontend code in many manners:
host it, mirror it, have it on GitHub, deploy it on IPFS, etc.
Enabling anyone to download this code and run in the browser,
making the webapp a truly decentralized dApp.

### 2. I am getting a `Module parse failed: Unexpected token` error

When using an older version of babel (used by `react-scripts`), the following error may appear when running the webapp:

```
./node_modules/multistream-select/src/ls.js 55:2
Module parse failed: Unexpected token (55:2)
File was processed with these loaders:
 * ./node_modules/babel-loader/lib/index.js
You may need an additional loader to handle the result of these loaders.
|   await pipe(protocolsReader, lp.decode(), async
|   /** @type {AsyncIterable<BufferList>} */
>   source => {
|     for await (const protocol of source) {
|       // Remove the newline
```

```
./node_modules/js-waku/build/module/lib/waku_relay/index.js 228:16
Module parse failed: Unexpected token (228:16)
File was processed with these loaders:
 * ./node_modules/react-scripts/node_modules/babel-loader/lib/index.js
You may need an additional loader to handle the result of these loaders.
|       }
|
>       meshPeers?.forEach(peer => {
|         toSend.add(peer);
|       });
```

As documented in issue [#165](https://github.com/status-im/js-waku/issues/165),
this error comes from an older babel version.
You need babel version **7.13.2** or above.

You can check your version using `npm ls`:

```
▶ npm ls @babel/preset-env
waku-pres@0.1.0
└─┬ react-scripts@4.0.3
  ├─┬ @svgr/webpack@5.5.0
  │ └── @babel/preset-env@7.12.17
  ├─┬ babel-preset-react-app@10.0.0
  │ └── @babel/preset-env@7.12.1
  └─┬ workbox-webpack-plugin@5.1.4
    └─┬ workbox-build@5.1.4
      └── @babel/preset-env@7.12.17 deduped
```

The best way to fix this is by using a more recent ReactJS stack.
This might not always possible, in this case force the installation of babel **7.14**:

```
npm i --save-dev @babel/preset-env@7.14
rm -rf node_modules package-lock.json
npm install
```