TanStack React Start (@tanstack/react-start)
This is the React Start entry skill. Use the workflow below, then load only the package skill that owns the boundary you are changing. Do not read start-core, Router Core, and React Router manuals in full before starting.
For React Server Components patterns, see react-start/server-components.
CRITICAL: All code is ISOMORPHIC by default. Loaders run on BOTH server and client. Use
createServerFnfor server-only logic.
CRITICAL: Do not confuse
@tanstack/react-startwith Next.js or Remix. They are completely different frameworks with different APIs.
CRITICAL: Types are FULLY INFERRED. Never cast, never annotate inferred values.
Full-Stack Workflow
- Define the route and component with
createFileRoute. - Put private or server-only reads and writes in
createServerFn; call reads directly from loaders. - Use
useServerFnfor component mutations, then invalidate the router or query cache after the write resolves. - Enforce auth in every private server function or server route. Add
beforeLoadseparately for navigation UX. - Run the initial SSR path, client navigation, mutation plus reload, direct anonymous endpoint request, runtime response assertion, type tests, and production build.
Load start-core/server-routes instead of server-functions only when a raw HTTP endpoint is required. Load router-core/* only for the specific routing concern involved, such as params or search validation.
Package API Surface
@tanstack/react-start re-exports everything from @tanstack/start-client-core plus:
useServerFn— React hook for calling server functions from components
All core APIs (createServerFn, createMiddleware, createStart, createIsomorphicFn, createServerOnlyFn, createClientOnlyFn) are available from @tanstack/react-start.
Server utilities (getRequest, getRequestHeader, setResponseHeader, setResponseHeaders, setResponseStatus) are imported from @tanstack/react-start/server.
Full Project Setup
1. Install Dependencies
npm i @tanstack/react-start @tanstack/react-router react react-dom
npm i -D vite @vitejs/plugin-react typescript @types/react @types/react-dom
2. package.json
{
"type": "module",
"scripts": {
"dev": "vite dev",
"build": "vite build",
"start": "node .output/server/index.mjs"
}
}
3. tsconfig.json
{
"compilerOptions": {
"jsx": "react-jsx",
"moduleResolution": "Bundler",
"module": "ESNext",
"target": "ES2022",
"skipLibCheck": true,
"strictNullChecks": true
}
}
4. vite.config.ts
import { defineConfig } from 'vite'
import { tanstackStart } from '@tanstack/react-start/plugin/vite'
import viteReact from '@vitejs/plugin-react'
export default defineConfig({
plugins: [
tanstackStart(), // MUST come before react()
viteReact(),
],
})
5. Router Factory (src/router.tsx)
import { createRouter } from '@tanstack/react-router'
import { routeTree } from './routeTree.gen'
export function getRouter() {
const router = createRouter({
routeTree,
scrollRestoration: true,
})
return router
}
6. Root Route (src/routes/__root.tsx)
import type { ReactNode } from 'react'
import {
Outlet,
createRootRoute,
HeadContent,
Scripts,
} from '@tanstack/react-router'
export const Route = createRootRoute({
head: () => ({
meta: [
{ charSet: 'utf-8' },
{ name: 'viewport', content: 'width=device-width, initial-scale=1' },
{ title: 'My TanStack Start App' },
],
}),
component: RootComponent,
})
function RootComponent() {
return (
<RootDocument>
<Outlet />
</RootDocument>
)
}
function RootDocument({ children }: Readonly<{ children: ReactNode }>) {
return (
<html>
<head>
<HeadContent />
</head>
<body>
{children}
<Scripts />
</body>
</html>
)
}
7. Index Route (src/routes/index.tsx)
import { createFileRoute } from '@tanstack/react-router'
import { createServerFn } from '@tanstack/react-start'
const getGreeting = createServerFn({ method: 'GET' }).handler(async () => {
return 'Hello from TanStack Start!'
})
export const Route = createFileRoute('/')({
loader: () => getGreeting(),
component: HomePage,
})
function HomePage() {
const greeting = Route.useLoaderData()
return <h1>{greeting}</h1>
}
useServerFn Hook
Use useServerFn to call server functions from React components with proper integration:
import { createServerFn, useServerFn } from '@tanstack/react-start'
const updatePost = createServerFn({ method: 'POST' })
.validator((data: { id: string; title: string }) => data)
.handler(async ({ data }) => {
await db.posts.update(data.id, { title: data.title })
return { success: true }
})
function EditPostForm({ postId }: { postId: string }) {
const updatePostFn = useServerFn(updatePost)
const [title, setTitle] = useState('')
return (
<form
(e) => {
e.preventDefault()
await updatePostFn({ data: { id: postId, title } })
}}
>
<input value={title} => setTitle(e.target.value)} />
<button type="submit">Save</button>
</form>
)
}
Global Start Configuration (src/start.ts)
import { createStart, createMiddleware } from '@tanstack/react-start'
const requestLogger = createMiddleware().server(async ({ next, request }) => {
console.log(`${request.method} ${request.url}`)
return next()
})
export const startInstance = createStart(() => ({
requestMiddleware: [requestLogger],
}))
React-Specific Components
All routing components from @tanstack/react-router work in Start:
<RouterProvider>— not needed in Start (handled automatically)<Outlet>— renders matched child route<Link>— type-safe navigation<Navigate>— declarative redirect<HeadContent>— renders head tags (must be in<head>)<Scripts>— renders body scripts (must be in<body>)<Await>— renders deferred data with Suspense<ClientOnly>— renders children only after hydration<CatchBoundary>— error boundary
Hooks Reference
All hooks from @tanstack/react-router work in Start:
useRouter()— router instanceuseRouterState()— subscribe to router stateuseNavigate()— programmatic navigationuseSearch({ from })— validated search paramsuseParams({ from })— path paramsuseLoaderData({ from })— loader datauseMatch({ from })— full route matchuseRouteContext({ from })— route contextRoute.useLoaderData()— typed loader data (preferred in route files)Route.useSearch()— typed search params (preferred in route files)
Common Mistakes
1. CRITICAL: Importing from wrong package
// WRONG — this is the SPA router, NOT Start
import { createServerFn } from '@tanstack/react-router'
// CORRECT — server functions come from react-start
import { createServerFn } from '@tanstack/react-start'
// CORRECT — routing APIs come from react-router (re-exported by Start too)
import { createFileRoute, Link } from '@tanstack/react-router'
2. HIGH: Using React hooks in beforeLoad or loader
// WRONG — beforeLoad/loader are NOT React components
beforeLoad: () => {
const auth = useAuth() // React hook, cannot be used here
}
// CORRECT — pass state via router context
const rootRoute = createRootRouteWithContext<{ auth: AuthState }>()({})
3. HIGH: Missing Scripts component
Without <Scripts /> in the root route's <body>, client JavaScript doesn't load and the app won't hydrate.
Cross-References
- start-core — core Start concepts
- router-core — routing fundamentals
- react-router — React Router hooks and components