# WebSocket

## Options

{% hint style="info" %}
See more about options [here](https://unetworking.github.io/uWebSockets.js/generated/interfaces/websocketbehavior.html)
{% endhint %}

### Exposed example

```javascript
import { exposeWebSocket } from 'nanoexpress/exposes/index.js';

app.ws('/ws', (req, res) => exposeWebSocket({
  console.log('Connecting...');

  res.on('connection', (ws) => {
    console.log('Connected');

    ws.on('message', (msg) => {
      console.log('Message received', msg);
      ws.send(msg);
    });
    ws.on('close', (code, message) => {
      console.log('Connection closed', { code, message });
    });
  });
  res.on('upgrade', () => {
    console.log('Connection upgrade');
  });
}));
```

### Basic example

{% hint style="warning" %}
Any polyfilled methods are unavailable here, But performance will be faster due to less layer cost.
{% endhint %}

```javascript
app.ws('/', {
  /* Options */
  compression: uWS.SHARED_COMPRESSOR,
  maxPayloadLength: 16 * 1024 * 1024,
  idleTimeout: 10,
  /* Handlers */
  open: (ws) => {
    console.log('A WebSocket connected!');
  },
  message: (ws, message, isBinary) => {
    /* Ok is false if backpressure was built up, wait for drain */
    let ok = ws.send(message, isBinary);
  },
  drain: (ws) => {
    console.log('WebSocket backpressure: ' + ws.getBufferedAmount());
  },
  close: (ws, code, message) => {
    console.log('WebSocket closed');
  }
});
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://nanoexpress.js.org/websocket.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.