Start Client Core

Core overview for TanStack Start: tanstackStart() Vite plugin, getRouter() factory, root route document shell (HeadContent, Scripts, Outlet), client/server entry points, routeTree.gen.ts, tsconfig configuration. Entry point for all Start skills.

Deploy to Cloudflare Workers, Netlify, Vercel, Node.js/Docker, Bun, Railway. Selective SSR (ssr option per route), SPA mode, static prerendering, ISR with Cache-Control headers, SEO and head management.

createMiddleware, request middleware (.server only), server function middleware (.client + .server), context passing via next({ context }), sendContext for client-server transfer, global middleware via createStart in src/start.ts, middleware factories, method order enforcement, fetch override precedence.

Server-side API endpoints using the server property on createFileRoute, HTTP method handlers (GET, POST, PUT, DELETE), createHandlers for per-handler middleware, handler context (request, params, context), request body parsing, response helpers, file naming for API routes.

Isomorphic-by-default principle, environment boundary functions (createServerFn, createServerOnlyFn, createClientOnlyFn, createIsomorphicFn), ClientOnly component, useHydrated hook, import protection, dead code elimination, environment variable safety (VITE_ prefix, process.env).

createServerFn (GET/POST), validator (Zod or function), useServerFn hook, server context utilities (getRequest, getRequestHeader, setResponseHeader, setResponseStatus), error handling (throw errors, redirect, notFound), streaming, FormData handling, file organization (.functions.ts, .server.ts).

Server-side authentication primitives for TanStack Start: session cookies (HttpOnly, Secure, SameSite, __Host- prefix), session read/issue/destroy via createServerFn and middleware, OAuth authorization-code flow with state and PKCE, password-reset enumeration defense, CSRF for non-GET RPCs, rate limiting auth endpoints, session rotation on privilege change. Pairs with router-core/auth-and-guards for the routing side.