> ## Documentation Index
> Fetch the complete documentation index at: https://docsuncv2.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# WebSocket.connect

Opens a WebSocket connection to a server and gives back a socket you can send and receive on.

```luau theme={null}
WebSocket.connect(url: string): WebSocket
```

<Warning>
  This is a WebSocket client only - you can't host a server with it.
</Warning>

Most commonly used to do things the Seliware sandbox can't do on its own. Your script can't open a browser window or touch the rest of the computer, but a small program running on the same machine can. The script talks to that program over a WebSocket and lets it do the work - for example, connect to a local server and send it a message every time the player picks up an item, so the local program opens a browser window.

## Parameters

| Parameter | Type     | Description                                      |
| --------- | -------- | ------------------------------------------------ |
| `url`     | `string` | The server URL. Starts with `ws://` or `wss://`. |

## Returns

A `WebSocket` socket object with this surface:

| Member                                       | Kind   | Description                                                                 |
| -------------------------------------------- | ------ | --------------------------------------------------------------------------- |
| `Send(message: string, is_binary: boolean?)` | method | Sends data to the server. `is_binary` is optional and defaults to `false`.  |
| `Close()`                                    | method | Closes the connection.                                                      |
| `OnMessage`                                  | event  | Fires when the server sends a message. The handler gets the message string. |
| `OnClose`                                    | event  | Fires when the connection closes.                                           |

## Example

<CodeGroup>
  ```luau Example 1 theme={null}
  local ws = WebSocket.connect("wss://echo.websocket.events")
  ws.OnMessage:Connect(function(message)
        print(message)
  end)
  ws:Send("Hello") -- Output: Hello
  ```

  ```luau Example 2 theme={null}
  local ws = WebSocket.connect("wss://echo.websocket.events")
  ws.OnClose:Connect(function()
        print("Closed")
  end)
  ws:Close() -- Output: Closed
  ```
</CodeGroup>

<Tip>
  This is a WebSocket client only - you can't host a server with it.
</Tip>