> For the complete documentation index, see [llms.txt](https://rxnode.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://rxnode.gitbook.io/docs/libs/core.md).

# core

### `observablify`

```typescript
function observablify<A extends Arguments, R extends Results = []>(
  fn: (...args: [...A, ErrorCallback<R>]) => any
): (...args: A) => Observable<VoidOrItemOrItems<R>>;
```

### `watchify`

```typescript
function watchify<A extends Arguments, R extends Results>(
  fn: (...args: [...A, Callback<R>]) => any,
  { closeOnUnsubscribe: closeOnUnsubscribe }?: { closeOnUnsubscribe?: boolean }
): (...args: A) => Observable<VoidOrItemOrItems<R>>;
```