> For the complete documentation index, see [llms.txt](https://www.rxjs.es/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.rxjs.es/api/indice/completionobserver.md).

# CompletionObserver

```typescript
interface CompletionObserver<T> {
  closed?: boolean;
  next?: (value: T) => void;
  error?: (err: any) => void;
  complete: () => void;
}
```

## Propiedades

| Propiedad | Tipo                 | Descripción |
| --------- | -------------------- | ----------- |
| closed    | `boolean`            |             |
| next      | `(value: T) => void` |             |
| error     | `(err: any) => void` |             |
| complete  | `() => void`         |             |