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# PubSub.Client

You can use the Client object to build a messaging system into the browser.

Example usage:

```js
import { PubSub } from "@signalwire/js";

const pubSubClient = new PubSub.Client({
  token: "<your chat token>", // get this from the REST APIs
});

await pubSubClient.subscribe(["mychannel1", "mychannel2"]);

pubSubClient.on("message", (message) => {
  // prettier-ignore
  console.log("Received", message.content,
              "on", message.channel,
              "at", message.publishedAt);
});

await pubSubClient.publish({
  channel: "mychannel1",
  content: "hello world",
});
```

## Constructor

Creates a new PubSub client.

```js
import { PubSub } from "@signalwire/js";

const pubSubClient = new PubSub.Client({
  token: "<your chat token>"
});
```

### Parameters

**`token`** `string` — required

SignalWire Chat token that can be obtained from the [REST APIs](/docs/apis/rest/chat-tokens/create-chat-token).

---

## Methods

#### [disconnect](/docs/browser-sdk/v3/js/reference/pubsub/client/disconnect)

Disconnect the client

#### [getAllowedChannels](/docs/browser-sdk/v3/js/reference/pubsub/client/get-allowed-channels)

Get channels allowed by the token

#### [publish](/docs/browser-sdk/v3/js/reference/pubsub/client/publish)

Publish a message to a channel

#### [subscribe](/docs/browser-sdk/v3/js/reference/pubsub/client/subscribe)

Subscribe to channels

#### [unsubscribe](/docs/browser-sdk/v3/js/reference/pubsub/client/unsubscribe)

Unsubscribe from channels

#### [updateToken](/docs/browser-sdk/v3/js/reference/pubsub/client/update-token)

Replace the client token

#### [on](/docs/browser-sdk/v3/js/reference/pubsub/client/on)

Subscribe to an event

#### [once](/docs/browser-sdk/v3/js/reference/pubsub/client/once)

Subscribe to an event once

#### [off](/docs/browser-sdk/v3/js/reference/pubsub/client/off)

Unsubscribe from an event

#### [removeAllListeners](/docs/browser-sdk/v3/js/reference/pubsub/client/remove-all-listeners)

Remove all event listeners

## Events

#### [Events](/docs/browser-sdk/v3/js/reference/pubsub/client/events)

Events emitted by the PubSub.Client class.

## Docs

- [Events](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/events.md)
- [disconnect](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/disconnect.md): disconnect method for the PubSub.Client class.
- [getAllowedChannels](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/get-allowed-channels.md): getAllowedChannels method for the PubSub.Client class.
- [off](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/off.md): off method for the PubSub.Client class.
- [on](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/on.md): on method for the PubSub.Client class.
- [once](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/once.md): once method for the PubSub.Client class.
- [publish](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/publish.md): publish method for the PubSub.Client class.
- [removeAllListeners](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/remove-all-listeners.md): removeAllListeners method for the PubSub.Client class.
- [subscribe](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/subscribe.md): subscribe method for the PubSub.Client class.
- [unsubscribe](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/unsubscribe.md): unsubscribe method for the PubSub.Client class.
- [updateToken](https://signalwire.com/docs/browser-sdk/v3/js/reference/pubsub/client/update-token.md): updateToken method for the PubSub.Client class.