/**
 * @license
 * Copyright 2025 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */
import { Event } from '../events/event.js';
import { BaseAgent } from './base_agent.js';
import { InvocationContext } from './invocation_context.js';
/**
 * A unique symbol to identify ADK agent classes.
 * Defined once and shared by all ParallelAgent instances.
 */
declare const PARALLEL_AGENT_SIGNATURE_SYMBOL: unique symbol;
/**
 * Type guard to check if an object is an instance of ParallelAgent.
 * @param obj The object to check.
 * @returns True if the object is an instance of ParallelAgent, false otherwise.
 */
export declare function isParallelAgent(obj: unknown): obj is ParallelAgent;
/**
 * A shell agent that run its sub-agents in parallel in isolated manner.
 *
 * This approach is beneficial for scenarios requiring multiple perspectives or
 * attempts on a single task, such as:
 *
 *  - Running different algorithms simultaneously.
 *  - Generating multiple responses for review by a subsequent evaluation agent.
 *
 * @deprecated Use `Workflow` instead, which expresses the same ordering as a
 * graph and adds routing, retries, HITL and resumability. This class will be
 * removed in a future version. Note that a `Workflow` cannot yet be an
 * `LlmAgent` sub-agent.
 */
export declare class ParallelAgent extends BaseAgent {
    /**
     * A unique symbol to identify ADK parallel agent class.
     */
    readonly [PARALLEL_AGENT_SIGNATURE_SYMBOL] = true;
    protected runAsyncImpl(context: InvocationContext): AsyncGenerator<Event, void, void>;
    protected runLiveImpl(_context: InvocationContext): AsyncGenerator<Event, void, void>;
}
export {};