import type { Server as HttpServer } from 'http';
/** Default path for the NATS WebSocket proxy endpoint. */
export declare const NATS_WS_PROXY_PATH = "/nats-ws";
/**
 * Derive the public NATS WebSocket URL from an HTTP request's headers.
 *
 * Respects `X-Forwarded-Proto` and `X-Forwarded-Host` so the correct
 * `wss://` scheme is used behind TLS-terminating load balancers.
 */
export declare function deriveWsUrlFromRequest(req: {
    headers: Record<string, string | string[] | undefined>;
}, basePath?: string): string;
/**
 * Attach a WebSocket proxy to an HTTP server that bridges browser
 * connections to an internal NATS WebSocket endpoint.
 *
 * The browser connects to `wss://domain.com{basePath}/nats-ws` (port 443,
 * through an ALB or reverse proxy). This handler upgrades the connection
 * and bridges bidirectionally to the internal NATS WS target.
 *
 * The proxy auto-derives the public `wsUrl` from the first incoming
 * request's headers, respecting `X-Forwarded-Proto` and `X-Forwarded-Host`
 * so the correct `wss://` scheme is used behind TLS-terminating load balancers.
 */
export declare function attachNatsWsProxy(server: HttpServer, target: string, options?: {
    basePath?: string;
    onWsUrlDerived?: (url: string) => void;
}): void;