import { Tool } from "@langchain/core/tools";
/**
 * Interface for parameters required by the SERPGoogleScholarAPITool class.
 */
export interface GoogleScholarAPIParams {
    /**
     * Optional API key for accessing the SerpApi service.
     */
    apiKey?: string;
}
/**
 * Tool for querying Google Scholar using the SerpApi service.
 */
export declare class SERPGoogleScholarAPITool extends Tool {
    /**
     * Specifies the name of the tool, used internally by LangChain.
     */
    static lc_name(): string;
    /**
     * Returns a mapping of secret environment variable names to their usage in the tool.
     * @returns {object} Mapping of secret names to their environment variable counterparts.
     */
    get lc_secrets(): {
        [key: string]: string;
    } | undefined;
    name: string;
    protected apiKey: string;
    /**
     * Description of the tool for usage documentation.
     */
    description: string;
    /**
     * Constructs a new instance of SERPGoogleScholarAPITool.
     * @param fields - Optional parameters including an API key.
     */
    constructor(fields?: GoogleScholarAPIParams);
    /**
     * Makes a request to SerpApi for Google Scholar results.
     * @param input - Search query string.
     * @returns A JSON string containing the search results.
     * @throws Error if the API request fails or returns an error.
     */
    _call(input: string): Promise<string>;
}