import type { Ref } from './types/outputs/Ref.js';
export interface FetchOpts<D = Response> extends Omit<RequestInit, 'signal'> {
    /**
     * Called before calling `fetch`, for logging purposes.
     *
     * @since 1.0.0
     */
    readonly onFetch?: (url: string | URL) => void;
    /**
     * Called on a successful fetch (with a status between 200 and 299)
     * Allows to parse the received response.
     *
     * @since 1.0.0
     */
    readonly onSuccess?: (res: Response) => PromiseLike<D>;
}
/**
 * Wraps a fetch call into an asynchronous Ref. Calls are deduplicated, meaning that if "defer" is called while a
 * previous first `fetch` call is still running, "defer" will not call `fetch` again but rather will "subscribe" to the
 * running call.
 *
 * @param url url to be fetched
 * @param opts options given to fetch.
 * @throws FetchError when the fetch call fails (received a response with a status > 200)
 *
 * @since 1.0.0
 * @see ref$
 */
export declare function fetch$<D>(url: string | URL, opts: FetchOpts & {
    onSuccess(res: Response): PromiseLike<D>;
}): Ref<Promise<D>>;
export declare function fetch$(url: string | URL, opts?: FetchOpts): Ref<Promise<Response>>;
/**
 * Error emitted on an unsuccessful fetch (with a status > 200)
 *
 * @since 1.0.0
 */
export declare class FetchError extends Error {
    readonly response: Response;
    constructor(response: Response);
    get status(): number;
}