import type { ScoringConfig, TrustScore } from './types.js';
import type { Storage } from './storage.js';
export declare class TrustEngine {
    private config;
    constructor(config?: ScoringConfig);
    /**
     * Compute trust score for a target agent from the perspective of `viewer`.
     * Uses direct experience + transitive graph walk + base reputation.
     */
    computeScore(target: string, viewer: string, storage: Storage): TrustScore;
    /**
     * BFS graph walk from viewer, collecting transitive trust signals.
     * Each hop decays by config.decayPerHop.
     */
    private computeTransitiveTrust;
    /**
     * Time-weighted average: recent ratings count more than old ones.
     * Weight decays by half every halfLifeDays.
     */
    private weightedAverage;
    /**
     * Filter out expired ratings.
     */
    private getValidRatings;
}