type NextHandler = (data: unknown) => void;
type ErrorHandler = (err: unknown) => void;
/** A live multiplexed Hasura subscription socket for one endpoint. */
export declare class HasuraWsClient {
    private readonly url;
    private readonly onStatus?;
    private ws;
    private acked;
    private closed;
    private nextId;
    private readonly subs;
    private reconnectTimer;
    private reconnectDelay;
    /**
     * Creates a subscription socket for one GraphQL endpoint.
     *
     * **Details**
     *
     * - `url`: ws:// or wss:// GraphQL endpoint.
     * - `onStatus`: Called with the live connection state (ack ⇒ true, drop ⇒ false).
     */
    constructor(url: string, onStatus?: ((connected: boolean) => void) | undefined);
    /**
     *  Register a subscription. It is (re)sent whenever the socket is live, and
     *  torn down on the returned unsubscribe.
     */
    subscribe(query: string, variables: Record<string, unknown>, onNext: NextHandler, onError?: ErrorHandler): () => void;
    /** Tear down the socket and forget every subscription. Idempotent. */
    close(): void;
    private start;
    private stop;
    private ensureSocket;
    private onMessage;
    private onDisconnect;
    private teardownSocket;
    private detach;
    private send;
}
export {};