> 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/getting-started/disaptch-a-message.md).

# Disaptch a message

## 📤 Dispatching a Message

Messages can be dispatched from anywhere in your application—such as services, controllers, scheduled jobs, or event listeners. This allows for clean, decoupled communication between parts of your system.

### 🚀 Example: Dispatch from an HTTP Controller

Here’s a simple example of dispatching a message when an HTTP request is made:

```ts
import { Controller, Get } from '@nestjs/common';
import { MessageBus, IMessageBus, RoutingMessage } from '@nestjstools/messaging';
import { SendMessage } from './test/send-message';

@Controller()
export class AppController {
  // You can inject any bus you've defined in your MessagingModule config
  constructor(@MessageBus('message.bus') private readonly messageBus: IMessageBus) {}

  @Get()
  async dispatchMessage(): Promise<string> {
    // Dispatching a SendMessage instance to the route 'your.message'
    await this.messageBus.dispatch(
      new RoutingMessage(new SendMessage('Message from HTTP request'), 'your.message'),
    );

    return 'Message dispatched successfully!';
  }
}
```

***

### 📦 Components Explained

| Component        | Purpose                                                          |
| ---------------- | ---------------------------------------------------------------- |
| `@MessageBus()`  | Injects a specific message bus by name.                          |
| `RoutingMessage` | Wraps the message and defines the route it should be sent to.    |
| `SendMessage`    | Your custom message class with data to transmit.                 |
| `dispatch()`     | Sends the message to all subscribed handlers matching the route. |

***

### 💡 Best Practices

* Use meaningful routing keys (e.g., `user.created`, `notification.send`).
* Define routing keys as the Enum

```
export enum EventMapper {
 UserCreated = 'my_app.event.user_created'
}
```

* Always wrap domain objects in proper message classes instead of sending raw payloads.


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