/** Lightweight metadata written alongside catalog-index.jsonl. */
export interface CatalogIndexMeta {
    /**
     * ISO-8601 timestamp of when the full index was last successfully written.
     * Used by staleness checks without reading the full JSONL.
     */
    builtAt: string;
    /**
     * Total number of entries written to the index at build time.
     * Informational — not used for freshness decisions.
     */
    entryCount: number;
}
/**
 * Returns `true` when a fresh `catalog-index.jsonl` exists on disk and its
 * age is within the configured `discoveryIndexMaxAgeDays` threshold.
 *
 * Falls back to checking the JSONL mtime when the meta file is absent so
 * that indexes written before this feature existed are still recognised.
 */
export declare function isCatalogIndexFresh(projectRoot: string): Promise<boolean>;
/**
 * Writes a `catalog-index-meta.json` file recording the build timestamp and
 * entry count. Called by `syncIndexedSourcesForIndex` after the JSONL is written.
 */
export declare function writeCatalogIndexMeta(projectRoot: string, entryCount: number): Promise<void>;
declare function assertCatalogIndexMeta(value: unknown, context: string): asserts value is CatalogIndexMeta;
/** Exposes narrow catalog-index internals for focused tests. */
export declare const catalogIndexInternals: {
    assertCatalogIndexMeta: typeof assertCatalogIndexMeta;
};
export {};