import type { LoadOptions } from "../types.js";
/**
 * Load environment variables from `.env` files into `process.env`.
 *
 * Automatically resolves the appropriate `.env` files based on `NODE_ENV`.
 * Supports file ordering, variable overriding, type generation, and file watching.
 *
 * @param options - Load options, a single path string, or an array of paths.
 *   When a string or array is passed, it's treated as the `paths` option.
 * @returns `true` if environment variables were loaded successfully, `false` otherwise.
 *
 * @example
 * ```ts
 * loadEnv();
 * loadEnv({ paths: [".env.local", ".env"], overrideExisting: true });
 * loadEnv(".env.production");
 * ```
 */
export declare function loadEnv(options?: LoadOptions | string | string[]): boolean;