/**
 * Subagent tool factory for AI SDK parent-child agent delegation.
 *
 * Creates a tool whose execute calls a subagent, optionally streaming
 * preliminary results and controlling what the model sees via toModelOutput.
 *
 * @see https://ai-sdk.dev/docs/agents/subagents
 */
import { type Tool } from 'ai';
/** Subagent interface compatible with ToolLoopAgent stream. */
export interface SubagentLike {
    stream(params: {
        prompt: string;
        abortSignal?: AbortSignal;
    }): Promise<{
        toUIMessageStream(): AsyncIterable<unknown> | ReadableStream<unknown>;
    }>;
    /** Optional: for passConversationHistory; when present, used instead of stream when messages are passed */
    generate?(params: {
        messages: {
            role: string;
            content: string | unknown[];
        }[];
        abortSignal?: AbortSignal;
    }): Promise<{
        text: string;
    }>;
}
export interface CreateSubagentToolOptions {
    /** Subagent to delegate to (ToolLoopAgent or compatible) */
    subagent: SubagentLike;
    /** Tool name (unique within the parent agent) */
    name?: string;
    /** Human-readable description for the LLM */
    description?: string;
    /** Input parameter name for the task (default: 'task') */
    taskParam?: string;
    /** Whether to extract summary for toModelOutput (default: true) */
    toModelSummary?: boolean;
    /** Pass full conversation history to subagent (opt-in; defeats context isolation; disables streaming) */
    passConversationHistory?: boolean;
}
/**
 * Create an AI SDK tool that delegates to a subagent.
 *
 * Supports streaming preliminary results via async generator execute.
 * When toModelSummary is true, toModelOutput extracts the last text part
 * so the parent model sees only a summary.
 *
 * @example
 * ```ts
 * const researchSubagent = new ToolLoopAgent({ model, instructions, tools });
 * const researchTool = createSubagentTool({
 *   subagent: researchSubagent,
 *   name: 'research',
 *   description: 'Research a topic in depth.',
 * });
 * const mainAgent = new ToolLoopAgent({
 *   model,
 *   tools: { research: researchTool },
 * });
 * ```
 */
export declare function createSubagentTool(options: CreateSubagentToolOptions): Tool<{
    task: string;
}, unknown>;