import type { GoogleGenerativeAIProvider } from '@ai-sdk/google';
/**
 * Gets a singleton instance of the GoogleGenerativeAI provider function.
 * Initializes the provider on first call.
 *
 * @param apiKey - If not provided, the provider will try to use the GEMINI_API_KEY environment variable.
 * @returns The initialized GoogleGenerativeAI provider function.
 */
export declare function getGoogleAIProvider(apiKey?: string): GoogleGenerativeAIProvider;