| [](https://pub.dev/packages/shelf_web_socket) |
| [](https://pub.dev/packages/shelf_web_socket/publisher) |
| |
| ## Web Socket Handler for Shelf |
| |
| `shelf_web_socket` is a [Shelf][] handler for establishing [WebSocket][] |
| connections. It exposes a single function, [webSocketHandler][], which calls an |
| `onConnection` callback with a [WebSocketChannel][] object for every |
| connection that's established. |
| |
| [Shelf]: https://pub.dev/packages/shelf |
| |
| [WebSocket]: https://tools.ietf.org/html/rfc6455 |
| |
| [webSocketHandler]: https://pub.dev/documentation/shelf_web_socket/latest/shelf_web_socket/webSocketHandler.html |
| |
| [WebSocketChannel]: https://pub.dev/documentation/web_socket_channel/latest/web_socket_channel/WebSocketChannel-class.html |
| |
| ```dart |
| import 'package:shelf/shelf_io.dart' as shelf_io; |
| import 'package:shelf_web_socket/shelf_web_socket.dart'; |
| |
| void main() { |
| var handler = webSocketHandler((webSocket, _) { |
| webSocket.stream.listen((message) { |
| webSocket.sink.add('echo $message'); |
| }); |
| }); |
| |
| shelf_io.serve(handler, 'localhost', 8080).then((server) { |
| print('Serving at ws://${server.address.host}:${server.port}'); |
| }); |
| } |
| ``` |