> For the complete documentation index, see [llms.txt](https://docs.nestjstools.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nestjstools.com/best-practice/create-wrapper-class-for-message-bus.md).

# Create wrapper class for Message Bus

### 🚀 Messaging Wrapper Module

This wrapper provides a reusable, centralized setup for working with the `@nestjstools/messaging` library. It encapsulates **sync-command** bus into injectable services that can be easily used across your application.

***

#### 📦 Purpose

Instead of configuring your message buses and channels in every module, this wrapper:

* Exposes  `SyncCommandBus` as injectable services
* Ensures clean separation of sync/async responsibilities
* Keeps your controller/service code lean and focused

***

```typescript
import { IMessageBus, RoutingMessage } from '@nestjstools/messaging';

/**
 * A simplified interface for dispatching messages through a configured message bus.
 * Encapsulates routing logic to keep controllers and services clean.
 */
export class InternalMessageBus {
  constructor(private readonly messageBus: IMessageBus) {}

  /**
   * Dispatch a message using the given routing key.
   *
   * @param message The payload (command/event/etc.)
   * @param routingKey The message routing key used by the bus
   */
  async dispatch(message: object, routingKey: string): Promise<void> {
    await this.messageBus.dispatch(new RoutingMessage(message, routingKey));
  }
}
```

#### 🧱 Module Setup

```ts
@Module({})
export class MessagingWrapperModule {
  static forRoot(): DynamicModule {
    return {
      imports: [
        MessagingModule.forRoot({
          buses: [
            { name: 'sync-command.bus', channels: ['sync-channel'] },
          ],
          channels: [
            new InMemoryChannelConfig({
              name: 'sync-channel',
            }),
      
          ],
          debug: true,
        }),
      ],
      providers: [
        {
          provide: 'MSyncCommandBus',
          useFactory: (bus: IMessageBus) => new MessageBus(bus),
          inject: ['sync-command.bus'],
        },
      ],
      exports: [
        'MSyncCommandBus',
      ],
      module: MessagingWrapperModule,
      global: true,
    };
  }
}
```

***

#### 🧩 Dependency Injection Tokens

These are helper tokens to inject the appropriate bus:

```ts
import { Inject } from '@nestjs/common';
import { Service } from '@messaging-wrapper/messaging-wrapper/dependency-injection/service';

export const SyncCommandBus = Inject('MSyncCommandBus');
```

***

#### 🧪 Usage in a Controller

Example of dispatching a command using the injected `@SyncCommandBus` :

```ts
@Controller('/orders')
export class OrderController {
  constructor(@SyncCommandBus private readonly commandBus: MessageBus) {}

  @Get('/simulate_complete')
  simulateCompleteOrder(): string {
    this.commandBus.dispatch(
      new CompleteOrder('uuid-order-123', 'Star Wars: The New Galactic', 2),
      'complete.order',
    );

    return 'ok';
  }
}
```


---

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