/**
 * Request utilities for vTilt tracking
 *
 * Handles HTTP requests with:
 * - GZip compression (via fflate)
 * - Multiple transport methods (fetch, XHR, sendBeacon)
 * - Automatic fallback between transports
 *
 * Compression transport split (important — see `utils/base64.ts`):
 *
 *   - fetch / XHR    → binary `Blob` of gzip bytes, body uses `compression=gzip-js`
 *   - sendBeacon     → base64 *text* of the same gzip bytes, body uses
 *                      `compression=base64`
 *
 *   `sendBeacon` with a binary `Blob` is unreliable on `pagehide` / tab
 *   discard: the browser queues the beacon synchronously but serializes the
 *   body *after* JS is torn down, and the underlying `ArrayBuffer` can be
 *   detached/GC'd by then. The wire body lands empty or truncated while the
 *   URL we already committed still carries `compression=gzip-js`, and the
 *   server's `gunzipSync` throws `Z_BUF_ERROR`. Switching the beacon to a
 *   base64 string body means `Blob([string])` owns its own UTF-8 copy, which
 *   survives unload reliably.
 *
 * Based on PostHog's request.ts pattern.
 */
import { Compression, jsonStringify } from "@v-tilt/core";
/**
 * Shared with the Node SDK via `@v-tilt/core` so both SDKs stay wire-compatible
 * with the ingestion endpoint. Re-exported here because the browser code (and
 * tests) historically import `Compression` / `jsonStringify` from `../request`.
 */
export { Compression, jsonStringify };
export interface RequestResponse {
    statusCode: number;
    text?: string;
    json?: any;
}
export interface RequestOptions {
    url: string;
    data?: any;
    method?: "POST" | "GET";
    headers?: Record<string, string>;
    transport?: "XHR" | "fetch" | "sendBeacon";
    compression?: Compression;
    timeout?: number;
    callback?: (response: RequestResponse) => void;
    /**
     * Project API token. When set, the helper authenticates the request:
     *
     *   - `fetch` / `XHR` transports → sent as an `x-api-key` header so the
     *     URL stays clean and is less likely to match ad/privacy blocker
     *     filter rules that look for `?token=` on known analytics origins.
     *   - `sendBeacon` transport → appended as `?token=<token>` because
     *     beacon requests cannot carry custom headers.
     *
     * The server accepts both (`x-api-key` is checked before the query
     * parameter), so older SDK versions that still embed the token in the
     * URL continue to work unchanged.
     */
    projectToken?: string;
}
export declare const request: (options: RequestOptions) => void;
export declare const requestAsync: (options: Omit<RequestOptions, "callback">) => Promise<RequestResponse>;
export declare const shouldCompress: (data: any) => boolean;