/**
 * Process-level cache for knowledge index snapshots.
 *
 * Knowledge sources are constructor-level static content. Multiple NeuroLink
 * instances in the same server process can therefore share the same immutable
 * lexical index instead of rebuilding it for every conversation/session.
 */
import type { KnowledgeFieldWeights, KnowledgeIndexSnapshot, KnowledgeSource, KnowledgeValidationResult } from "../types/index.js";
export declare const KNOWLEDGE_INDEX_CACHE_LIMIT = 32;
/**
 * Cache key intentionally uses source/version metadata, not conversation scope.
 * The source content hash prevents stale reuse even when a host forgets to bump
 * a source version after changing entries.
 */
export declare const buildKnowledgeIndexCacheKey: (sources: KnowledgeSource[], fallbackVersion: string, weights: KnowledgeFieldWeights) => string;
export declare const getOrBuildKnowledgeIndexSnapshot: (sources: KnowledgeSource[], fallbackVersion: string, weights: KnowledgeFieldWeights) => Promise<{
    snapshot: KnowledgeIndexSnapshot | null;
    validation: KnowledgeValidationResult;
}>;