splitLink and simple subscription onPostAdd as in example from docs page(https://trpc.io/docs/client/links/httpSubscriptionLink)api.post.onPostAdd type of onPostAdd is(property) onPostAdd: DecorateProcedure<SubscriptionProcedure<{...}> (property) onPostAdd: {
useSubscription: ProcedureUseSubscription<{
...
}>;
}