export interface KeysCommandIO {
    stdout: {
        write: (s: string) => boolean;
    };
    stderr: {
        write: (s: string) => boolean;
    };
    exit: (code: number) => void;
    /** Returns the secret key read from stdin (piped or interactive masked). */
    readKeyFromStdin: () => Promise<string>;
    /** True if stdin is piped (non-TTY). */
    isPiped: () => boolean;
}
export declare function keysCommand(subcommand: string | undefined, arg: string | undefined, io?: KeysCommandIO): Promise<void>;