/**
 * Set origin to a function implementing some custom logic. The function takes the
 * request origin as the first parameter and a callback (which expects the signature
 * err [object], allow [bool]) as the second.
 *
 * @see https://github.com/expressjs/cors
 *
 * @publicApi
 */
export declare type CustomOrigin = (requestOrigin: string, callback: (err: Error | null, allow?: boolean) => void) => void;
/**
 * Interface describing CORS options that can be set.
 *
 * @see https://github.com/expressjs/cors
 * @publicApi
 */
export interface CorsOptions {
    /**
     * Configures the `Access-Control-Allow-Origins` CORS header.  See [here for more detail.](https://github.com/expressjs/cors#configuration-options)
     */
    origin?: boolean | string | RegExp | (string | RegExp)[] | CustomOrigin;
    /**
     * Configures the Access-Control-Allow-Methods CORS header.
     */
    methods?: string | string[];
    /**
     * Configures the Access-Control-Allow-Headers CORS header.
     */
    allowedHeaders?: string | string[];
    /**
     * Configures the Access-Control-Expose-Headers CORS header.
     */
    exposedHeaders?: string | string[];
    /**
     * Configures the Access-Control-Allow-Credentials CORS header.
     */
    credentials?: boolean;
    /**
     * Configures the Access-Control-Max-Age CORS header.
     */
    maxAge?: number;
    /**
     * Whether to pass the CORS preflight response to the next handler.
     */
    preflightContinue?: boolean;
    /**
     * Provides a status code to use for successful OPTIONS requests.
     */
    optionsSuccessStatus?: number;
}