import type { StorageBackend, VectorEntry, VectorEntryType, VectorSearchResult } from '../../types/index.js';
/**
 * JSON fallback storage backend.
 * Used when better-sqlite3 is not available.
 */
export declare class JsonFallbackBackend implements StorageBackend {
    private readonly filePath;
    private cache;
    constructor(projectId: string);
    private load;
    private save;
    insert(entry: VectorEntry): Promise<void>;
    update(id: string, partial: Partial<VectorEntry>): Promise<void>;
    delete(id: string): Promise<void>;
    getById(id: string): Promise<VectorEntry | undefined>;
    getAll(type?: VectorEntryType): Promise<VectorEntry[]>;
    searchSimilar(embedding: number[], topK: number, threshold: number, type?: VectorEntryType): Promise<VectorSearchResult[]>;
}
/** Reset the warning flag (for testing). */
export declare function resetJsonFallbackWarning(): void;
//# sourceMappingURL=json-fallback.d.ts.map