# PdfRequestOptions reference

Controls how string and URL sources are fetched: extra `fetch` options, a replacement fetcher and the handling of HTTP errors.

## Used by

- [Authenticated requests](https://react-pdf-viewer-chi.vercel.app/react-pdf-viewer/authenticated-requests.md)

## Import

```ts
import type { PdfRequestOptions } from '@kingtech/react-pdf-viewer';
```

## Properties

| Name | Type | Default | Required | Description |
| --- | --- | --- | --- | --- |
| `requestInit` | `RequestInit` | — | No | Extra `fetch` options for URL sources: headers, `credentials`, `mode`, … |
| `fetcher` | `(url: string, init: RequestInit) => Promise<Response>` | — | No | Replaces `fetch` entirely, e.g. with an authenticated HTTP client. |
| `onHttpError` | `(response: Response) => boolean \| void \| Promise<boolean \| void>` | — | No | Called for non-2xx responses. Return `true` when handled (e.g. after redirecting to sign-in): the viewer shows its empty state and does not call `onError`. |
| `getHttpErrorMessage` | `(response: Response) => Promise<string>` | — | No | Builds the `HTTP_ERROR` message. Return `undefined` for the default: an RFC 7807 `detail`, then `title`, then a JSON string body, then `Failed to fetch PDF: {status} {statusText}`. |

## Source

[packages/react-pdf-viewer/src/types.ts](https://github.com/kiralygyula92/react-pdf-viewer/blob/main/packages/react-pdf-viewer/src/types.ts#L116)