import type * as x from 'x-value';
import type { RouteMatchOptions } from './router.js';
export declare const TUNNEL_PORT_DEFAULT: number & Record<typeof x.__nominal, {
    integer: true;
}> & Record<typeof x.__type, number> & Record<typeof x.__nominal, {
    port: true;
}>;
export declare const INITIAL_WINDOW_SIZE: number;
export declare const MAX_OUTSTANDING_PINGS = 5;
export type ConnectionId = x.Nominal<'connection id', number>;
export declare const TUNNEL_HEADER_NAME = "x-tunnel";
export type TunnelId = x.Nominal<'tunnel id', number>;
export type TunnelStreamId = x.Nominal<'tunnel stream id', number>;
export type TunnelInOutHeaderData = {
    type: 'in-out-stream';
    id: TunnelStreamId;
    host: string;
    port: number;
};
export type TunnelOutInHeaderData = {
    type: 'tunnel';
    alias: string | undefined;
    routeMatchOptions: RouteMatchOptions;
    password?: string;
} | {
    type: 'out-in-stream';
    id: TunnelStreamId;
};
export type TunnelOutInTunnelResponseHeaderData = {
    alias: string | undefined;
};
export type TunnelOutInErrorResponseHeaderData = {
    error: string;
};
export declare function encodeTunnelHeader<T>(data: T): string;
export declare function decodeTunnelHeader<T>(header: string): T | undefined;