# WsProxy

**Kind:** Class

**Source:** [`packages/websockets/context/ws-proxy.ts`](https://github.com/nestjs/nest/blob/master/packages/websockets/context/ws-proxy.ts#L6)

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

`WsProxy` creates an asynchronous proxy function for WebSocket-backed operations. It centralizes request forwarding and error handling so callers can invoke WebSocket actions through a Promise-based interface.

## Methods

| Method | Signature | Returns |
|---|---|---|
| `create` | `create(targetCallback: (...args: unknown[]) => Promise<any>, exceptionsHandler: WsExceptionsHandler, targetPattern: string)` | `(...args: unknown[]) => Promise<any>` |
| `handleError` | `handleError(exceptionsHandler: WsExceptionsHandler, args: unknown[], error: T)` | `void` |

## When something fails

- `WsProxy` handles failure in 1 place: it logs it and continues in all 1.

## Diagram

```mermaid
graph LR
  Client[Application Code] --> Proxy[WsProxy]
  Proxy --> Create[create()]
  Create --> Handler[Async Proxy Function]
  Handler --> Socket[WebSocket Context]
  Socket --> Response[Promise Result]
  Socket --> Error[handleError()]
  Error --> Client
```

## Usage

```ts
import { WsProxy } from '@your-package/websockets';

// Construct the proxy with the WebSocket context/configuration required
// by your application.
const wsProxy = new WsProxy(/* websocket context */);

// Create the async function used to invoke WebSocket-backed operations.
const invoke = wsProxy.create();

try {
  const result = await invoke('users.get', { id: 'user-123' });

  console.log('WebSocket response:', result);
} catch (error) {
  console.error('WebSocket request failed:', error);
}
```

## AI Coding Instructions

- Use `create()` once per configured proxy instance and retain the returned async function for WebSocket calls.
- Treat calls through the created proxy as asynchronous and always `await` them or return their Promise.
- Route transport and remote-operation failures through `handleError()` rather than duplicating WebSocket error normalization in callers.
- Ensure the WebSocket context is initialized and connected before invoking the function returned by `create()`.
- Preserve the proxy’s argument forwarding behavior when extending it; proxy calls may accept arbitrary argument lists.

## Relationships

- IMPORTS → `ExecutionContextHost`