/**
 * Orchestration aggregation — builds a structured prompt from task results
 * and spawns a single aggregation subagent to synthesize them.
 */
import type { OrchestrationSpawnFn } from "./orchestration-engine.js";
import type { OrchestrationTaskResult } from "./orchestration-types.js";
/**
 * Format task results into a structured prompt section, appending the
 * user's aggregation prompt at the end.
 */
export declare function buildAggregationPrompt(results: OrchestrationTaskResult[], userPrompt: string): string;
/**
 * Spawn a single aggregation subagent that synthesizes all task results.
 * Returns the aggregation result text or null on failure.
 */
export declare function runAggregation(params: {
    aggregationPrompt: string;
    results: OrchestrationTaskResult[];
    orchestrationDir: string;
    spawnFn: OrchestrationSpawnFn;
    aggregationTemplate?: string;
}): Promise<string | null>;
