What problem does it solve? Fetching and caching route data in TanStack Router involves subtle behaviors—loaders run on the client by default, staleTime defaults to 0, and search params do not automatically reach loaders—which leads to stale data, unnecessary refetches, and runtime crashes when developers apply server-side or React-hook assumptions. ## Core Features & Use Cases - Loader and Cache Configuration: Set up route loaders with loaderDeps cache keys, staleTime/gcTime SWR caching, and pendingComponent states with pendingMs/pendingMinMs timing. - Context and Dependency Injection: Use createRootRouteWithContext to inject auth, API clients, and hook values into loaders and beforeLoad without calling hooks inside route functions. - Deferred Loading and Invalidation: Return unawaited promises from loaders, render them with the Await component, and re-run loaders after mutations with router.invalidate. - Use Case: When building a paginated posts page, declare loaderDeps from validated search params so the loader refetches only when offset or limit changes, while unrelated params like sort direction leave the cache untouched. ## Quick Start Ask the AI to add a loader with loaderDeps, pendingComponent, and error handling to a TanStack Router route that fetches paginated data from an API.
