/**
 * Where a captured session lives on disk.
 *
 * `substack-mcp login` writes here so the cookie does not have to sit in a
 * client config file. The file is 0600 and encrypted with AES-256-GCM under a
 * key derived from this OS account plus this machine, which is never stored.
 *
 * Be honest about what that buys: a copied file is useless on another machine,
 * and a casual disk or backup read sees ciphertext. It is machine-binding and
 * obfuscation, not a secret vault. Code running as you on this machine can
 * re-derive the key. That is the same exposure as the environment-variable
 * path, which is why env vars remain a first-class, fully supported option.
 */
export type StoredSession = {
    publication_url: string;
    session_token: string;
    user_id?: string;
    captured_at: string;
};
export declare function sessionHome(): string;
export declare function sessionPath(): string;
export declare function saveSession(session: StoredSession): string;
/** Read the stored session, or null if there is none or it will not decrypt. */
export declare function loadSession(): StoredSession | null;
export declare function sessionDir(): string;