/**
 * @license
 * Copyright 2026 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */
import { BaseLlm } from './base_llm.js';
import { BaseLlmConnection } from './base_llm_connection.js';
import { LlmRequest } from './llm_request.js';
import { LlmResponse } from './llm_response.js';
/**
 * Type definition for a function that selects a model based on the request.
 */
export type LlmRouter = (models: Readonly<Record<string, BaseLlm>>, request: LlmRequest, errorContext?: {
    failedKeys: ReadonlySet<string>;
    lastError: unknown;
}) => Promise<string | undefined> | string | undefined;
/**
 * A BaseLlm implementation that delegates to one of multiple models based on a router function.
 */
export declare class RoutedLlm extends BaseLlm {
    private readonly models;
    private readonly router;
    constructor({ models, router, modelName, }: {
        models: Readonly<Record<string, BaseLlm>> | BaseLlm[];
        router: LlmRouter;
        modelName?: string;
    });
    /**
     * Generates content by delegating to the selected model.
     */
    generateContentAsync(llmRequest: LlmRequest, stream?: boolean): AsyncGenerator<LlmResponse, void>;
    /**
     * Creates a live connection to the LLM by delegating to the selected model.
     * This live connection cannot be switched mid-stream, it is tied to the model
     * selected at the time of connection.
     */
    connect(llmRequest: LlmRequest): Promise<BaseLlmConnection>;
}