Solid Start (@tanstack/solid-start)

This skill builds on start-core. Read start-core first for foundational concepts.

This skill covers the Solid-specific bindings, setup, and patterns for TanStack Start.

CRITICAL: All code is ISOMORPHIC by default. Loaders run on BOTH server and client. Use createServerFn for server-only logic.

CRITICAL: Do not confuse @tanstack/solid-start with SolidStart (@solidjs/start). They are completely different frameworks with different APIs.

CRITICAL: Types are FULLY INFERRED. Never cast, never annotate inferred values.

Package API Surface

@tanstack/solid-start re-exports everything from @tanstack/start-client-core plus:

useServerFn — Solid hook for calling server functions from components

All core APIs (createServerFn, createMiddleware, createStart, createIsomorphicFn, createServerOnlyFn, createClientOnlyFn) are available from @tanstack/solid-start.

Server utilities (getRequest, getRequestHeader, setResponseHeader, setCookie, getCookie, useSession) are imported from @tanstack/solid-start/server.

Full Project Setup

1. Install Dependencies

npm i @tanstack/solid-start @tanstack/solid-router solid-js
npm i -D vite vite-plugin-solid typescript

2. package.json

json

{
  "type": "module",
  "scripts": {
    "dev": "vite dev",
    "build": "vite build",
    "start": "node .output/server/index.mjs"
  }
}

3. tsconfig.json

json

{
  "compilerOptions": {
    "jsx": "preserve",
    "jsxImportSource": "solid-js",
    "moduleResolution": "Bundler",
    "module": "ESNext",
    "target": "ES2022",
    "skipLibCheck": true,
    "strictNullChecks": true
  }
}

4. vite.config.ts

import { defineConfig } from 'vite'
import { tanstackStart } from '@tanstack/solid-start/plugin/vite'
import solidPlugin from 'vite-plugin-solid'

export default defineConfig({
  plugins: [
    tanstackStart(), // MUST come before solid plugin
    solidPlugin({ ssr: true }),
  ],
})

5. Router Factory (src/router.tsx)

tsx

import { createRouter } from '@tanstack/solid-router'
import { routeTree } from './routeTree.gen'

export function getRouter() {
  const router = createRouter({
    routeTree,
    scrollRestoration: true,
  })
  return router
}

6. Root Route (src/routes/__root.tsx)

tsx

import {
  Outlet,
  createRootRoute,
  HeadContent,
  Scripts,
} from '@tanstack/solid-router'
import { HydrationScript } from 'solid-js/web'
import { Suspense } from 'solid-js'

export const Route = createRootRoute({
  head: () => ({
    meta: [
      { charSet: 'utf-8' },
      { name: 'viewport', content: 'width=device-width, initial-scale=1' },
      { title: 'My TanStack Start App' },
    ],
  }),
  // shellComponent renders the HTML document shell (always SSR'd)
  shellComponent: RootDocument,
})

function RootDocument(props: { children: any }) {
  return (
    <html>
      <head>
        <HydrationScript />
      </head>
      <body>
        <HeadContent />
        <Suspense>{props.children}</Suspense>
        <Scripts />
      </body>
    </html>
  )
}

7. Index Route (src/routes/index.tsx)

tsx

import { createFileRoute } from '@tanstack/solid-router'
import { createServerFn } from '@tanstack/solid-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 Solid components with automatic redirect handling:

tsx

import { createServerFn, useServerFn } from '@tanstack/solid-start'
import { createSignal } from 'solid-js'

const updatePost = createServerFn({ method: 'POST' })
  .inputValidator((data: { id: string; title: string }) => data)
  .handler(async ({ data }) => {
    await db.posts.update(data.id, { title: data.title })
    return { success: true }
  })

function EditPostForm(props: { postId: string }) {
  const updatePostFn = useServerFn(updatePost)
  const [title, setTitle] = createSignal('')

  return (
    <form
      onSubmit={async (e) => {
        e.preventDefault()
        await updatePostFn({ data: { id: props.postId, title: title() } })
      }}
    >
      <input value={title()} onInput={(e) => setTitle(e.target.value)} />
      <button type="submit">Save</button>
    </form>
  )
}

Unlike the React version, useServerFn does NOT wrap the returned function in any memoization (no useCallback equivalent needed — Solid's setup runs once).

Solid-Specific Components

All routing components from @tanstack/solid-router work in Start:

<Outlet> — renders matched child route
<Link> — type-safe navigation
<Navigate> — declarative redirect
<HeadContent> — renders head tags via @solidjs/meta (must be in <body> — uses portals to inject into <head>)
<Scripts> — renders body scripts (must be in <body>)
<Await> — renders deferred data with <Suspense>
<ClientOnly> — renders children only after hydration
<CatchBoundary> — error boundary wrapping Solid.ErrorBoundary

Hooks Reference

All hooks from @tanstack/solid-router work in Start. Most return Accessor<T> — call the accessor to read:

useRouter() — router instance (NOT an Accessor)
useRouterState() — Accessor<T>, subscribe to router state
useNavigate() — navigation function (NOT an Accessor)
useSearch({ from }) — Accessor<T>, validated search params
useParams({ from }) — Accessor<T>, path params
useLoaderData({ from }) — Accessor<T>, loader data
useMatch({ from }) — Accessor<T>, full route match
useRouteContext({ from }) — Accessor<T>, route context
Route.useLoaderData() — Accessor<T>, typed loader data (preferred in route files)
Route.useSearch() — Accessor<T>, typed search params (preferred in route files)

Common Mistakes

1. CRITICAL: Importing from wrong package

tsx

// WRONG — this is the SPA router, NOT Start
import { createServerFn } from '@tanstack/solid-router'

// CORRECT — server functions come from solid-start
import { createServerFn } from '@tanstack/solid-start'

// CORRECT — routing APIs come from solid-router (re-exported by Start too)
import { createFileRoute, Link } from '@tanstack/solid-router'

2. CRITICAL: Forgetting to call Accessor

Most hooks return Accessor<T>. Must call to read the value.

tsx

// WRONG
const data = Route.useLoaderData()
return <h1>{data.message}</h1>

// CORRECT
const data = Route.useLoaderData()
return <h1>{data().message}</h1>

3. HIGH: Missing Scripts component

Without <Scripts /> in the root route's <body>, client JavaScript doesn't load and the app won't hydrate.

4. HIGH: Solid plugin before Start plugin in Vite config

// WRONG
plugins: [solidPlugin(), tanstackStart()]

// CORRECT
plugins: [tanstackStart(), solidPlugin()]

Cross-References

start-core — core Start concepts
router-core — routing fundamentals
solid-router — Solid Router hooks and components