import { MessageProcessor, ProcessingPayload } from '@hawk.so/core';
/**
 * Enriches payload with browser environment data:
 * viewport dimensions, user agent, current URL, and GET parameters.
 */
export declare class BrowserAddonMessageProcessor implements MessageProcessor<'errors/javascript'> {
    /**
     * Reads current browser state (window dimensions, user agent, URL, GET params) and
     * merges it into `payload.addons`, preserving any addons already set.
     *
     * @param payload - event message payload to enrich
     * @returns modified payload with browser addons merged in
     */
    apply(payload: ProcessingPayload<'errors/javascript'>): ProcessingPayload<'errors/javascript'> | null;
    /**
     * Parses `window.location.search` into plain key-value object.
     *
     * @returns parsed GET parameters, or `undefined` if URL has no query string
     */
    private parseGetParams;
}