# ContentFetcher

Learn how to type the slot content fetcher.

This type represents a callback that fetches a slot's content.

## Signature \[#signature]

This type has the following definition:

```ts
type ContentFetcher = (id: string) => Promise<FetchResponse | undefined>;
```

The callback receives the slot ID and resolves to the slot's content response. Resolving to `undefined` leaves the block's own content in place, which is how the integration skips personalization in the Storyblok visual editor.