import { FetchMethod } from './fetchVal';
/**
 * Represents a CSRF error.
 */
export declare class CsrfError extends Error {
    /**
     * Used for a type guard check.
     */
    readonly _isCsrfError = true;
    /**
     * HTTP response code.
     */
    readonly status: number;
    constructor(response: Response, message?: string);
}
/**
 * A type guard for an CSRF error.
 *
 * @param value The value to check.
 * @returns The result of the type guard check.
 */
export declare function isCsrfError(value: unknown): value is CsrfError;
/**
 * Clear any cached CSRF tokens.
 *
 * Calling this will force all CSRF tokens to be re-requested on subsequent network calls.
 */
export declare function clearFinCsrfTokens(): void;
/**
 * Asynchronously return the CSRF token for the specified host.
 *
 * @param host The host.
 * @returns Resolves to the CSRF token or an empty string if it can't be found.
 */
export declare function getFinCsrfToken(host: string): Promise<string>;
/**
 * An enhanced fetch API for CSRF token management with the FIN framework.
 *
 * Transparently handles CSRF token management (a.k.a. attest keys) and provides additional
 * features for working with haystack data.
 *
 * @link https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch
 *
 * @param resource The resource to request.
 * @param options Optional object containing any custom settings.
 * @param fetchFunc Optional fetch function to use instead of global fetch.
 * @returns A promise that resolves to a response object.
 */
export declare function finCsrfFetch(resource: RequestInfo, options?: RequestInit, fetchFunc?: FetchMethod): Promise<Response>;
export interface CsrfRequestInit extends RequestInit {
    attestHeaderName?: string;
    attestRequestUri?: string;
    attestResponseHeaderName?: string;
}
export declare function isCsrfRequestInit(value?: RequestInit): value is CsrfRequestInit;