docs.waku.org/docs/clients/js-waku/quick-start.mdx

---
title: Quick Start
date: 2021-12-09T14:00:00+01:00
weight: 20
---

# Quick Start

In this guide, you will learn how to integrate Waku into an **existing** JavaScript project.
If you're looking to build a Waku app from scratch, check out our [Build a Chat App](./build-chat-app) guide.

## 1. Install Waku Libraries

To begin, install the required Waku libraries with the following command:

```shell
npm i @waku/core @waku/create @waku/utils
```

## 2. Start a Waku Node

Next, create and start a Waku Node:

```js
import {createLightNode} from "@waku/create"

const waku = await createLightNode({defaultBootstrap: true})
await waku.start()
```

:::info

Setting the `defaultBootstrap` option to true allows your Waku node to connect to a set of pre-defined nodes.

:::

## 3. Wait for Connection to be Established

Your Waku node needs to connect to a remote node in order to access the network.
To wait for this, use the `waitForRemotePeer` function:

```js
import * as waku from "@waku/core"

await waku.waitForRemotePeer(wakuNode)
```

## 4. Define a Content Topic

The `contentTopic` is a metadata `string` used for categorizing messages on the Waku Network.
Depending on your use case, you can create one or more new `contentTopic`(s).
Refer to our [How to Choose a Content Topic](/) guide more details.

For this guide, we'll use `/quick-start/1/message/utf8`.
Note that our payload will be encoded using `utf-8`.
We recommended using Protobuf for production purposes.

```js
const contentTopic = `/quick-start/1/message/utf8`
```

## 5. Create a Decoder

Waku supports various encryption protocols.
A decoder allows you to specify the content topic to use and how to decrypt messages.
For the chosen content topic, create a plain text decoder (without encryption):

```js
const decoder = waku.createDecoder(contentTopic)
```

## 6. Listen for Incoming Messages

Messages sent over the network are `Waku Message`s,
as defined in the [14/WAKU2-MESSAGE](https://rfc.vac.dev/spec/14/#wire-format) RFC.

Messages returned by the plain text decoder implement the [`DecodedMessage`](https://js.waku.org/classes/_waku_core.DecodedMessage.html) interface.

For now, we will just use the `payload` field.
It is a byte array field that can be used to encode any data.
We will store messages as a `utf-8` string.

To listen for messages using the decoder, use the following code:

```js

wakuNode.filter.subscribe([decoder], (message) => {
    const str = utils.bytesToUtf8(message.payload)
    // str is a string, render it in your app as desired
})
```

## 7. Send Messages

Finally, create a `sendMessage` function that sends messages over Waku:

```js
import * as utils from "@waku/utils"

const encoder = waku.createEncoder(contentTopic)

const sendMessage = async (textMsg) => {
    await wakuNode.lightPush.push(encoder, {
        payload: utils.utf8ToBytes(textMsg),
    });
};
```

Now, you can use the `sendMessage` function in your app to send messages.

## Conclusion

Congratulations! You've successfully added decentralized communication features to your app.

Continue learning by exploring how to [build a chat app](./build-chat-app) from scratch using Waku.