| name | start-core |
| description | 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. |
| type | core |
| library | tanstack-start |
| library_version | 1.166.2 |
| sources | ["TanStack/router:docs/start/framework/react/build-from-scratch.md","TanStack/router:docs/start/framework/react/quick-start.md","TanStack/router:docs/start/framework/react/guide/routing.md"] |
TanStack Start Core
TanStack Start is a full-stack React framework built on TanStack Router and Vite. It adds SSR, streaming, server functions (type-safe RPCs), middleware, server routes, and universal deployment.
CRITICAL: All code in TanStack Start is ISOMORPHIC by default — it runs in BOTH server and client environments. Loaders run on both server AND client. To run code exclusively on the server, use createServerFn. This is the #1 AI agent mistake.
CRITICAL: TanStack Start is NOT Next.js. Do not generate getServerSideProps, "use server" directives, app/layout.tsx, or any Next.js/Remix patterns. Use createServerFn for server-only code.
CRITICAL: Types are FULLY INFERRED. Never cast, never annotate inferred values.
Sub-Skills
Quick Decision Tree
Need to run code exclusively on the server (DB, secrets)?
→ start-core/server-functions
Need auth checks, logging, or shared logic across server functions?
→ start-core/middleware
Need to understand where code runs (server vs client)?
→ start-core/execution-model
Need a REST API endpoint (GET/POST/PUT/DELETE)?
→ start-core/server-routes
Need to deploy, configure SSR, or prerender?
→ start-core/deployment
Project Setup
1. Install Dependencies
npm i @tanstack/react-start @tanstack/react-router react react-dom
npm i -D vite @vitejs/plugin-react typescript
2. Configure Vite
import { defineConfig } from 'vite'
import { tanstackStart } from '@tanstack/react-start/plugin/vite'
import viteReact from '@vitejs/plugin-react'
export default defineConfig({
plugins: [
tanstackStart(),
viteReact(),
],
})
3. Create Router Factory
import { createRouter } from '@tanstack/react-router'
import { routeTree } from './routeTree.gen'
export function getRouter() {
const router = createRouter({
routeTree,
scrollRestoration: true,
})
return router
}
4. Create Root Route with Document Shell
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 App' },
],
}),
component: RootComponent,
})
function RootComponent() {
return (
<html>
<head>
<HeadContent />
</head>
<body>
<Outlet />
<Scripts />
</body>
</html>
)
}
5. Create Index Route with Server Function
import { createFileRoute } from '@tanstack/react-router'
import { createServerFn } from '@tanstack/react-start'
const getGreeting = createServerFn({ method: 'GET' }).handler(async () => {
return { message: 'Hello from the server!' }
})
export const Route = createFileRoute('/')({
loader: () => getGreeting(),
component: HomePage,
})
function HomePage() {
const data = Route.useLoaderData()
return <h1>{data.message}</h1>
}
Common Mistakes
1. CRITICAL: React plugin before Start plugin in Vite config
plugins: [react(), tanstackStart()]
plugins: [tanstackStart(), react()]
2. HIGH: Enabling verbatimModuleSyntax in tsconfig
verbatimModuleSyntax causes server bundles to leak into client bundles. Keep it disabled.
3. HIGH: Missing Scripts component in root route
The <Scripts /> component must be rendered in the <body> of the root route. Without it, client-side JavaScript does not load and hydration fails.
function RootComponent() {
return (
<html>
<head>
<HeadContent />
</head>
<body>
<Outlet />
</body>
</html>
)
}
function RootComponent() {
return (
<html>
<head>
<HeadContent />
</head>
<body>
<Outlet />
<Scripts />
</body>
</html>
)
}
Version Note
This skill targets @tanstack/react-start v1.166.2 and @tanstack/start-client-core v1.166.2.
