/** Check if a raw inbound message is large enough to offload to Worker. */
export declare function isLargeMessage(raw: string): boolean;
/** Check if an outbound message object is large enough to offload.
 *  Avoids JSON.stringify by checking known large-payload shapes (file attachments). */
export declare function isLargeOutbound(msg: unknown): boolean;
/** Parse a large message in a Worker thread. Falls back to inline on failure. */
export declare function workerParseMessage(raw: string, sessionKey: Uint8Array | null): Promise<Record<string, unknown> | null>;
/** Serialize+encrypt a large message in a Worker thread, then send via ws. */
export declare function workerEncryptAndSend(ws: {
    send: (data: string) => void;
    readyState: number;
}, msg: unknown, sessionKey: Uint8Array | null): Promise<void>;
/** Shut down all workers. Call on server shutdown. */
export declare function terminateWorkerPool(): Promise<void>;