TanStack Frontend Patterns

Overview

Implement TanStack Router routes with project-standard TRPC integration, loader strategy, typed inference, and form handling. Follow this document for decision rules, then use references/ for full examples.

Core Patterns

1) Define routes with loader-driven data strategy

• Define each route with createFileRoute(...) and a loader that preloads critical data.
• Read params/search from route APIs (Route.useParams(), Route.useSearch()) in components.
• Keep examples in references/router-loader-examples.md.

2) Choose loader prefetch strategy intentionally

• Use await prefetchQuery(...) for data required in first paint.
• Use await Promise.all([...]) for multiple critical queries.
• Use void prefetchQuery(...) only for secondary data.
• Use fetchQuery(...) when loader logic needs returned data.
• Apply the void rule together with the Suspense rule below.

See full decision trees and performance tradeoffs in references/prefetch-patterns.md.

3) Enforce Suspense boundaries for void-prefetched data

• Wrap every component that consumes void prefetchQuery(...) data via useSuspenseQuery(...) in <Suspense>.
• Treat missing boundaries as correctness bugs (hydration risk), not optional optimization.
• Cross-check any void decision against this requirement before finalizing the route.

See examples and the loader-pattern decision table in references/prefetch-patterns.md.

4) Apply TRPC v11 TanStack Query pattern

Use one rule block consistently:

• Use TanStack Query hooks (useQuery, useSuspenseQuery, useMutation) with TRPC factory methods.
• Use .queryOptions(...) for queries/prefetch and .mutationOptions(...) for mutations.
• Use .queryKey(...) for cache invalidation.
• Do not call .useQuery() or .useMutation() on TRPC procedures.

See concise do/don't examples in references/trpc-v11-query-pattern.md.

5) Prefer RouterInputs/RouterOutputs for inference

• Prefer RouterInputs/RouterOutputs for input/response typing across route components and helpers.
• Allow explicit local types when they represent UI-only view models, external library contracts, or deliberate narrowing/aggregation that does not mirror server payloads.
• Avoid duplicating raw TRPC response shapes as hand-written app types.

See practical inference patterns in references/type-inference.md.

6) Use the project form wrapper (not raw TanStack Form)

• Treat "TanStack Form" in this template as useAppForm + @/shared/forms/* field components.
• Compose forms with shared form components and pass form/field explicitly.
• Avoid raw TanStack Form hooks in feature code unless updating the shared form infrastructure itself.

See complete form patterns in references/form-patterns.md.

7) Follow frontend conventions

• Prefer type Props = ... naming for component props.
• Use absolute imports (@/...).
• Import shared cross-package types from @project/common.
• Invalidate TRPC cache through queryKey(...) helpers.

Resources

references/

• router-loader-examples.md - Complete route definition examples
• prefetch-patterns.md - Performance optimization and prefetch strategies
• trpc-v11-query-pattern.md - Compact TRPC v11 query/mutation/invalidation rules
• form-patterns.md - Form handling with validation examples
• type-inference.md - TRPC type inference patterns and examples