/**
 * Options for creating a storage adapter.
 */
export interface StorageOptions {
    /**
     * The root URL of the storage backend. Useful if you want to host your own
     * storage backend behind a different URL.
     */
    rootUrl?: string;
    /**
     * A storage authentication token that will be used when authenticating at the
     * backend. Note that the library will automatically renew the token if
     * authentication fails. Hence, you will still need to provide the bot token.
     */
    jwt?: string;
}
/**
 * @param token The bot token of your bot.
 * @param opts Further configuration options
 * @returns An adapter to grammY's free session storage
 */
export declare function freeStorage<T>(token: string, opts?: StorageOptions): {
    readAllKeys(): Promise<T>;
    read(key: string): Promise<T>;
    write(key: string, data: T): Promise<void>;
    delete(key: string): Promise<void>;
    /**
     * Returns the storage authentication token which is used to store the
     * session data. Only useful if you want to avoid the login call that will
     * be performed automatically when the storage adapter contacts its backend
     * for the first time. This can improve startup performance and is
     * especially useful in serverless environments.
     */
    getToken(): Promise<string>;
};