ck:tanstack

TanStack

Build full-stack React apps with TanStack Start, manage forms with TanStack Form, and add AI features with TanStack AI.

When to Activate

• User mentions TanStack Start, TanStack Form, or TanStack AI
• Building full-stack React app with file-based routing + server functions
• Creating forms with type-safe validation (Zod/Valibot)
• Adding AI chat/streaming to a TanStack app
• Comparing TanStack Start vs Next.js/Remix

Quick Start — TanStack Start

npm create @tanstack/start@latest    # create project
npm run dev                          # dev server :3000
npm run build                        # production build

Project Structure

src/
├── routes/
│   ├── __root.tsx          # root layout (required)
│   ├── index.tsx           # /
│   └── posts.$postId.tsx   # /posts/:postId
├── router.tsx              # createRouter config
├── routeTree.gen.ts        # AUTO-GENERATED — never edit
└── start.ts                # global middleware
app.config.ts               # Nitro/Start config

Server Function

import { createServerFn } from '@tanstack/react-start'
import { z } from 'zod'

const getUser = createServerFn({ method: 'GET' })
  .validator(z.object({ id: z.string() }))
  .handler(async ({ data }) => db.user.findUnique({ where: { id: data.id } }))

Route with Loader

export const Route = createFileRoute('/posts/$postId')({
  loader: ({ params }) => getPost({ data: { id: params.postId } }),
  component: PostComponent,
})
function PostComponent() {
  const post = Route.useLoaderData()
  return <div>{post.title}</div>
}

Middleware

import { createMiddleware } from '@tanstack/react-start'
export const authMiddleware = createMiddleware()
  .server(async ({ next, context }) => {
    const session = await getSession(context.request)
    return next({ context: { user: session.user } })
  })

TanStack Form

Headless, type-safe form library. Detailed API: references/tanstack-form.md

import { useForm } from '@tanstack/react-form'
import { zodValidator } from '@tanstack/zod-form-adapter'

const form = useForm({
  defaultValues: { email: '', age: 0 },
  validatorAdapter: zodValidator,
  onSubmit: async ({ value }) => { await saveUser(value) },
})

// JSX: <form.Field name="email" validators={{ onChange: z.string().email() }}>
//   {(f) => <input value={f.state.value} onChange={e => f.handleChange(e.target.value)} />}
// </form.Field>