/**
 * In-memory inverted index over session transcripts (`sessions.json` + JSONL).
 */
import type { AgentMessage } from '@earendil-works/pi-agent-core';
export declare class SessionSearchIndex {
    private sessions;
    private globalWordIndex;
    /**
     * Scan `sessionsRoot` (flat `sessions.json` + per-session `.jsonl` transcripts).
     */
    buildIndex(sessionsRoot: string): Promise<void>;
    search(query: string, limit?: number): Array<{
        key: string;
        score: number;
    }>;
    getSessionMessages(key: string): AgentMessage[];
    private buildWordIndex;
    private mergeContextTextIntoWordIndex;
    private mergeIntoGlobalIndex;
}
