Instruction file imported from georgestander/redChatHeavy (.cursor/rules/lazy-prefetch-pattern.mdc). Copyright stays with the author.

Lazy prefetch pattern (React Query v5 + Next RSC)

Goal: start prefetchQuery() early on the server without awaiting, so it doesn't block SSR / Suspense, while still hydrating on the client.

Requirements (repo-specific)

• QueryClient must dehydrate pending queries.
  • In this repo that's in trpc/query-client.ts:
    • dehydrate.shouldDehydrateQuery includes query.state.status === "pending".
    • dehydrate.serializeData / hydrate.deserializeData use SuperJSON.

Pattern

In a Server Component (e.g. app/(chat)/layout.tsx):

• Create/get the request-scoped query client (getQueryClient() from @/trpc/server)
• Kick off prefetches with void (no await):
  • void queryClient.prefetchQuery(trpc.foo.bar.queryOptions(...))
• Let HydrateClient/HydrationBoundary dehydrate the cache.

Use await only for data you must have before rendering (everything else should be lazy-prefetched).