export type HeaderValue = string | string[] | undefined | null;
/**
 * The proxy behavior that is passed to the proxy handler. This is a subset of
 * request objects that are used by different frameworks, like Express and NextJS.
 */
export interface ProxyBehavior<ResponseType> {
    id: string;
    method: string;
    respondWith(status: number, data: string | any): ResponseType;
    sendResponse(response: Response): Promise<ResponseType>;
    getHeaders(): Record<string, HeaderValue>;
    getHeader(name: string): HeaderValue;
    sendHeader(name: string, value: string): void;
    getRequestBody(): Promise<string | undefined>;
    /** @deprecated Use `resolveFalAuth` in `ProxyConfig` instead. */
    resolveApiKey?: () => Promise<string | undefined>;
}