/**
 * Supported authentication types for IT Glue API.
 * @typedef {'apiKey'} AuthType
 */
export type AuthType = 'apiKey';
declare const _apiKey: unique symbol;
/**
 * Handles authentication for the IT Glue API client.
 * Currently supports API key authentication.
 *
 * @class
 * @example
 * const auth = new AuthHandler('your-api-key');
 * const headers = auth.getAuthHeaders();
 */
export declare class AuthHandler {
    #private;
    /** @private */
    private [_apiKey];
    /**
     * Create a new AuthHandler instance.
     * @param {string} apiKey - The IT Glue API key.
     * @param {AuthType} [authType='apiKey'] - The authentication type.
     * @throws Will throw if the API key is missing or empty.
     */
    constructor(apiKey: string, authType?: AuthType);
    /**
     * Get the current API key.
     * @returns {string} The API key.
     */
    getApiKey(): string;
    /**
     * Get authentication headers for API requests.
     * @returns {Object} An object containing authentication headers.
     * @example
     * const headers = auth.getAuthHeaders();
     */
    getAuthHeaders(): {
        [key: string]: string;
    };
    /**
     * Clear the stored API key.
     * @returns {void}
     */
    clearApiKey(): void;
}
export {};