TanStack Query And cRPC

Default

Use generated cRPC query and mutation options as the owner of query keys, functions, input typing, and result typing. Do not hand-build parallel keys or duplicate the transport contract in components.

Convex-backed cRPC queries are live subscriptions unless the API explicitly documents a non-live path. A successful mutation normally updates subscribed queries through Convex; blind invalidation is redundant and can cause churn.

Colocation

• Keep a query in the smallest component or hook that owns its loading, empty, error, permission, and success states.
• Hoist only when siblings share the same result or a route owns preload.
• Keep presentation components data-agnostic when that improves reuse.
• Use component colocation rules before inventing a feature-wide data layer.

Query Pattern

const result = useQuery(
  crpc.projects.list.queryOptions({ workspaceId }),
);

Use skipToken, an explicit enabled condition, or the generated auth-aware option when required input or session authority is missing. Do not send fake identifiers to keep a hook unconditional.

Mutation Pattern

const createProject = useMutation(
  crpc.projects.create.mutationOptions({
    onSuccess: (project) => {
      router.push(`/projects/${project.id}`);
    },
  }),
);

Own user feedback at the mutation boundary. Disable duplicate submission, surface the actual error, and preserve form input on failure.

Do not invalidate a live cRPC query by habit. Invalidation is allowed only when the consumer is demonstrably non-subscribed, the source is HTTP/external, a manual cache entry was written, or a server-side/RSC snapshot needs a bounded refresh. Name that exception beside the code.

RSC And Preload

• Prefer server callers for server-owned rendering and authorization.
• Use the package's supported preload/hydration path when a client component must adopt server-fetched data.
• Never create a second query-key dialect for RSC.
• Treat server snapshots and live client subscriptions as different lifetimes; document which one owns freshness.
• Avoid importing client-only Query machinery into Convex functions or other server-only package entries.

Cache Operations

Use generated filters/options for getQueryData, setQueryData, cancellation, and invalidation. An optimistic update must define rollback and reconciliation with the live Convex result. If subscription delivery is fast enough, prefer pending UI over speculative cache mutation.

Proof

Test the owner, not TanStack Query itself:

• query is skipped until required identity/input exists;
• mutation pending/error/success states are honest;
• live data changes without a redundant refetch;
• bounded invalidation affects only the intended non-live key;
• RSC hydration and client adoption use one key contract;
• permission failures never render stale privileged data.