AbstractWsAdapter

Kind: Class

Source: packages/websockets/adapters/ws-adapter.ts

Part of: Websockets

AbstractWsAdapter is the base class for WebSocket transport adapters in NestJS. It provides shared lifecycle behavior for client connection/disconnection events and server cleanup, while concrete adapters implement server creation and message-handler binding for a specific WebSocket library.

Implements: WebSocketAdapter

Methods

Properties

Diagram

mermaid
graph LR
  App[Nest Application] --> Adapter[AbstractWsAdapter]
  Adapter --> Create[create()]
  Adapter --> Connect[bindClientConnect()]
  Adapter --> Disconnect[bindClientDisconnect()]
  Adapter --> Messages[bindMessageHandlers()]
  Adapter --> Close[close() / dispose()]
  Create --> Server[WebSocket Server]
  Server --> Client[WebSocket Client]
  Client --> Messages

Usage

ts
import { AbstractWsAdapter } from '@nestjs/websockets';

class CustomWsAdapter extends AbstractWsAdapter<MyServer, MyClient> {
  create(port: number): MyServer {
    return createMyWebSocketServer(port);
  }

  bindMessageHandlers(client: MyClient, handlers, transform) {
    client.on('message', async rawMessage => {
      const message = JSON.parse(rawMessage.toString());

      for (const handler of handlers) {
        if (handler.message === message.event) {
          const response = await transform(
            handler.callback(message.data, client),
          );

          client.send(JSON.stringify(response));
        }
      }
    });
  }
}

// main.ts
async function bootstrap() {
  const app = await NestFactory.create(AppModule);

  app.useWebSocketAdapter(new CustomWsAdapter(app));
  await app.listen(3000);
}

AI Coding Instructions

• Extend AbstractWsAdapter rather than instantiating it directly; implement create() and bindMessageHandlers() for the chosen WebSocket library.
• Use bindClientConnect() and bindClientDisconnect() to attach lifecycle callbacks instead of duplicating connection event wiring.
• Ensure incoming messages are parsed and routed to the matching Nest gateway handler in bindMessageHandlers().
• Always support adapter cleanup through close() and dispose(), especially when the underlying server keeps open client connections.
• Register the concrete adapter with app.useWebSocketAdapter() during application bootstrap.

Used by

2 references from 2 files. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

Imported by (2)

• IoAdapter — packages/platform-socket.io/adapters/io-adapter.ts:14
• WsAdapter — packages/platform-ws/adapters/ws-adapter.ts:39