import type { SecretsStore } from './index.js';
/**
 * Filesystem fallback for `SecretsStore`. Writes to `<rootDir>/nat-secrets.json`
 * with mode 0o600.
 *
 * This is NOT a substitute for the OS keychain — the file is plain JSON, only
 * protected by POSIX permissions. We use it only when keytar is unavailable
 * and the caller has been warned (see `createSecretsStore`).
 *
 * Windows: chmod is a no-op (mode bits don't apply), so the file is readable
 * by any user on the same machine. This is documented.
 */
export declare class FileSecretsStore implements SecretsStore {
    private readonly path;
    constructor(rootDir: string);
    filePath(): string;
    set(account: string, value: string): Promise<void>;
    get(account: string): Promise<string | null>;
    delete(account: string): Promise<boolean>;
    list(): Promise<string[]>;
    private load;
    private save;
}