/**
 * 获取当前页面的域
 * @example https://www.baidu.com/s?wd=hello&ie=utf-8 => .baidu.com
 * @example https://127.0.0.1:5000/dashboard => 127.0.0.1
 * @example http://localhost:3000/test => localhost
 */
export declare function getDomain(): string | undefined;
/**
 * 拼接 url 路径，自动处理多余的 /
 * @param {...string[]} parts 路径片段
 * @returns {string}
 * @example urlJoin('https://www.baidu.com', 's', 'wd=hello') => https://www.baidu.com/s/wd=hello
 * @example urlJoin('/', 'ai/copywriting/gen') => /ai/copywriting/gen
 */
export declare function urlJoin(...parts: string[]): string;
/**
 * 获取 headers 中指定 key 的值（不区分大小写）
 * @param headers - headers 对象
 * @param key - 要查找的 key
 * @returns 找到的 header 值，未找到返回 undefined
 * @example getHeaderValue(headers, 'content-type') => 'application/json'
 * @example getHeaderValue(headers, 'Content-Type') => 'application/json'
 */
export declare function getHeaderValue(headers: Record<string, any>, key: string): any;
