method WorkersBroker.prototype.respond WorkersBroker.prototype.respond<TReq, TRes>(topic: string,handler: RequestHandler<TReq, TRes>,options?: SubscribeOptions): Promise<ISubscription> Registers a responder for a request topic. Type Parameters TReq The request payload type TRes The reply payload type Parameters topic: string The request topic to respond on handler: RequestHandler<TReq, TRes> Invoked per request; its result is returned to the caller optional options: SubscribeOptions queue load-balances across members of one group Return Type Promise<ISubscription> The active subscription Throws CloudflareUnsupportedError When the messaging.rpc arm is absent