# WebSocketServer

**Kind:** Function

**Source:** [`packages/websockets/decorators/gateway-server.decorator.ts`](https://github.com/nestjs/nest/blob/master/packages/websockets/decorators/gateway-server.decorator.ts#L8)

**Part of:** [Websockets](subsystem-packages-websockets)

Attaches native Web Socket Server to a given property.

`WebSocketServer()` is a property decorator that attaches the underlying native WebSocket server instance to a gateway class property. Nest initializes the property after the gateway is created, allowing gateway methods to emit events, broadcast messages, or access adapter-specific server APIs.

## Signature

```ts
function WebSocketServer(): PropertyDecorator
```

**Returns:** `PropertyDecorator`

## Diagram

```mermaid
graph LR
  A[WebSocketGateway] --> B[WebSocketServer Decorator]
  B --> C[Gateway Server Property]
  D[Nest WebSockets Runtime] --> E[Create Native Server]
  E --> C
  C --> F[Emit or Broadcast Events]
```

## Usage

```ts
import {
  SubscribeMessage,
  WebSocketGateway,
  WebSocketServer,
} from '@nestjs/websockets';
import { Server, Socket } from 'socket.io';

@WebSocketGateway()
export class EventsGateway {
  @WebSocketServer()
  server: Server;

  @SubscribeMessage('message')
  handleMessage(client: Socket, payload: { text: string }) {
    this.server.emit('message', {
      from: client.id,
      text: payload.text,
    });
  }
}
```

## AI Coding Instructions

- Use `@WebSocketServer()` only on gateway class properties decorated with `@WebSocketGateway()`.
- Type the decorated property with the native server implementation used by the configured adapter, such as Socket.IO's `Server`.
- Do not manually instantiate or assign the server property; Nest populates it during gateway initialization.
- Use the injected server for server-wide operations such as `emit`, room broadcasting, and adapter-specific APIs.
- Ensure event handlers account for the selected WebSocket adapter, since native server APIs differ between Socket.IO and `ws`.

## 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)

- `EventsGateway` — `sample/02-gateways/src/events/events.gateway.ts`:12
- `EventsGateway` — `sample/16-gateways-ws/src/events/events.gateway.ts`:11