name: tanstack-start description: TanStack Start (RC) full-stack React with server functions, SSR, Cloudflare Workers. Use for Next.js migration, edge rendering, or encountering hydration, auth, data pattern errors. license: MIT allowed-tools: [Bash, Read, Write, Edit] metadata: version: 1.0.0-rc.1 author: Claude Skills Maintainers last-verified: 2025-12-09 production-tested: false status: rc keywords: - tanstack start - tanstack react start - full-stack react - selective ssr - spa mode - static prerender - server functions - server routes

cloudflare workers
edge rendering
hydration errors
next.js migration

TanStack Start (React) — RC-Ready Playbook

Full-stack React on TanStack Router with per-route SSR/CSR, file-based routing, server functions, and first-class Cloudflare Workers support.

Use this skill when

Building a greenfield React app that needs route-level SSR/CSR/SSG switches.
Migrating from Next.js/React Router while keeping file-based routing + API routes.
Shipping to edge runtimes (Workers) with typed server functions and bindings.
You want predictable routing with type-safe params/search + built-in preloading.

What’s inside

References: quickstart/layout, rendering modes, server functions, Cloudflare hosting, execution/auth, plus new routing/data/navigation/devtools guides.
Script: scripts/bootstrap-cloudflare-start.sh <app> scaffolds Start + Workers + binding types.
Troubleshooting: hydration, API routing, bindings, navigation/preloading failures.

Quick Start (React)

npm create @tanstack/start@latest my-app
cd my-app
npm run dev

Manual installs (all bundle targets are supported): add @tanstack/react-router + @tanstack/react-start with your bundler plugin (vite, webpack, or esbuild) per the official install guides.

Core layout reminder

app/routes/** file-based routes → router tree, automatic code-splitting + data preloading.
app/entry.client.tsx hydrates <StartClient />; app/entry.server.tsx wraps createServerEntry.
app/config.ts or app/start.ts sets defaultSsr, spaMode, middleware, and context.

Routing + Data Best Practices

Type-safe params & search: createFileRoute() infers path params; add validateSearch (zod) to parse and coerce search params.
Route matching order is deterministic (index → static → dynamic → splat); rely on this when adding catch-alls.
Loaders run once per location change; return plain data, throw redirect()/notFound() for control flow.
Data mutations: colocate action/server functions; keep loaders read-only and invalidate via router.invalidate() after mutation.
TanStack Query bridge: create a QueryClient in router context and ensureQueryData inside loaders to dedupe fetches.
Deferred/external data: stream partial data or read from external loaders; prefer suspense-friendly responses.
Head management: set head per route for <title>/meta; derive from loader data to keep SEO consistent.
Not-found/auth: throw notFound() or redirect() in loaders/middleware; use error boundaries for UX.

Example route (typed search + data-only SSR):

// app/routes/posts.$postId.tsx
import { createFileRoute, redirect } from '@tanstack/react-router'
import { z } from 'zod'

export const Route = createFileRoute('/posts/$postId')({
  validateSearch: z.object({ preview: z.boolean().optional() }),
  ssr: 'data-only',
  loader: async ({ params, search, context }) => {
    const post = await context.queryClient.ensureQueryData(['post', params.postId], () =>
      fetch(`/api/posts/${params.postId}?preview=${!!search.preview}`).then(r => r.json())
    )
    if (!post.published && !search.preview) throw redirect({ to: '/drafts' })
    return { post }
  },
})

Navigation, Preloading, and UX

Link prefetch defaults: <Link preload="intent"> (hover/focus) preloads route data/code; use preload="render" for above-the-fold routes.
Programmatic preloading: router.preloadRoute({ to, search }) to warm caches before navigation (e.g., on visibility).
Route masking: keep canonical URLs while showing user-friendly masks (e.g., /products?slug=abc masked as /p/abc).
Navigation blocking: protect unsaved forms with router.navigate({ to, replace, from }) blockers or useBlocker.
Scroll restoration: enable scrollRestoration to restore positions on back/forward; customize per route when using long lists.
Search param serialization: customize parse/stringify to keep numbers/dates stable and avoid stringified booleans.

Rendering & Performance

Per-route SSR: set ssr: true | false | 'data-only' on routes; defaultSsr config sets the baseline.
Code-splitting: file-based routes auto-split; add lazy/load for manual chunks on code-based routes.
Preloading strategy: pair preload="intent" links with defaultPreloadStaleTime to avoid over-fetching.
Render optimizations: keep loaders pure, memoize heavy components, and use pendingComponent for CSR routes to avoid layout shift.

Devtools, Linting, and LLM Support

Add <RouterDevtools /> during development to inspect matches, loader states, and preloading.
Enable the ESLint plugin @tanstack/eslint-plugin-router with the recommended config to enforce inference-sensitive property order (e.g., beforeLoad before loader).
LLM-aware routing: the Router exposes structured route metadata to LLM agents; keep descriptions concise in Route meta for better AI navigation.

Deployment Notes (Cloudflare-friendly)

Keep cloudflare({ viteEnvironment: { name: 'ssr' } }) first in Vite plugins so bindings reach server entry.
Regenerate bindings after changes: npm run cf-typegen.
For static-heavy sites, enable prerender to ship HTML to Workers Assets/Pages; exclude param routes or add explicit pages.

Ship Checklist

Routes load without hydration warnings (prefer ssr: 'data-only' for non-deterministic UI).
Search params validated with validateSearch and custom serializer where needed.
Link preloading configured for high-traffic routes; blockers added for unsaved forms.
ESLint plugin enabled (create-route-property-order rule) and npm run check passes.
Devtools verified locally; router.matches state looks correct.
Cloudflare bindings typed (cf-typegen) and streaming tested via curl -N.

Unnamed Skill

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