Tanstack Start Expert

Use when adding auth to a TanStack Start app — route protection, server-function authorization, sessions, CSRF. Do NOT use for generic route guards.

Use when scaffolding a TanStack Start project, wiring the build tool, or debugging setup (blank page, hydration, no client JS).

Use when building or deploying a TanStack Start app — Cloudflare, Netlify, Vercel/Node/Bun, prerendering, or env vars. Do NOT use for app logic or generic Vite config.

Use when composing cross-cutting server logic in TanStack Start with createMiddleware — chaining, context, auth factories.

Use when loading data in Start routes — isomorphic loaders, TanStack Query in a loader, mutations, or per-route SSR. Do NOT use for generic Router/Query API.

Use when building raw HTTP endpoints in TanStack Start with the server property — handlers, params, middleware. Do NOT use for internal RPC (start-server-functions).

Use when organizing TanStack Start code, splitting oversized routes/server functions, or reviewing architecture. Do NOT use for setup or plain React SPA.

Use when deciding where TanStack Start code runs, fixing secret leaks, DB-in-loader bugs, or hydration mismatches.

Use when creating type-safe RPC server logic with createServerFn — validators, handlers, FormData, redirects. Do NOT use for raw HTTP endpoints or middleware chains.