Tanstack Start Client Core Start Core Deployment

Deployment and Rendering

TanStack Start deploys to any hosting provider via Vite and Nitro. This skill covers hosting setup, SSR configuration, prerendering, and SEO.

Hosting Providers

Cloudflare Workers

pnpm add -D @cloudflare/vite-plugin wrangler

// vite.config.ts
import { defineConfig } from 'vite'
import { tanstackStart } from '@tanstack/react-start/plugin/vite'
import { cloudflare } from '@cloudflare/vite-plugin'
import viteReact from '@vitejs/plugin-react'

export default defineConfig({
  plugins: [
    cloudflare({ viteEnvironment: { name: 'ssr' } }),
    tanstackStart(),
    viteReact(),
  ],
})

// wrangler.jsonc
{
  "name": "my-app",
  "compatibility_date": "2025-09-02",
  "compatibility_flags": ["nodejs_compat"],
  "main": "@tanstack/react-start/server-entry",
}

Deploy: npx wrangler login && pnpm run deploy

Worker env is per-request. Cloudflare Workers inject env vars at request time. process.env.X at module scope evaluates to undefined even on the server. The Cloudflare-canonical way to read env (including from module scope) is the cloudflare:workers env binding:

import { env } from 'cloudflare:workers'
const apiHost = env.API_HOST

Or read process.env.X per-request inside .handler() / middleware .server(). See Cloudflare's environment-variables docs and start-core/execution-model.

Netlify

pnpm add -D @netlify/vite-plugin-tanstack-start

// vite.config.ts
import { defineConfig } from 'vite'
import { tanstackStart } from '@tanstack/react-start/plugin/vite'
import netlify from '@netlify/vite-plugin-tanstack-start'
import viteReact from '@vitejs/plugin-react'

export default defineConfig({
  plugins: [tanstackStart(), netlify(), viteReact()],
})

Deploy: npx netlify deploy

Nitro (Vercel, Railway, Node.js, Docker)

npm install nitro@npm:nitro-nightly@latest

// vite.config.ts
import { defineConfig } from 'vite'
import { tanstackStart } from '@tanstack/react-start/plugin/vite'
import { nitro } from 'nitro/vite'
import viteReact from '@vitejs/plugin-react'

export default defineConfig({
  plugins: [tanstackStart(), nitro(), viteReact()],
})

Build and start: npm run build && node .output/server/index.mjs

Bun

Bun deployment requires React 19. For React 18, use Node.js deployment.

// vite.config.ts — add bun preset to nitro
plugins: [tanstackStart(), nitro({ preset: 'bun' }), viteReact()]

Selective SSR

Control SSR per route with the ssr property.

ssr: true (default)

Runs beforeLoad and loader on server, renders component on server:

export const Route = createFileRoute('/posts/$postId')({
  ssr: true, // default
  loader: () => fetchPost(), // runs on server during SSR
  component: PostPage, // rendered on server
})

ssr: false

Disables server execution of beforeLoad/loader and server rendering:

export const Route = createFileRoute('/dashboard')({
  ssr: false,
  loader: () => fetchDashboard(), // runs on client only
  component: DashboardPage, // rendered on client only
})

ssr: 'data-only'

Runs beforeLoad/loader on server but renders component on client only:

export const Route = createFileRoute('/canvas')({
  ssr: 'data-only',
  loader: () => fetchCanvasData(), // runs on server
  component: CanvasPage, // rendered on client only
})

Functional Form

Decide SSR at runtime based on params/search:

export const Route = createFileRoute('/docs/$docType/$docId')({
  ssr: ({ params }) => {
    if (params.status === 'success' && params.value.docType === 'sheet') {
      return false
    }
  },
})

SSR Inheritance

Children inherit parent SSR config and can only be MORE restrictive:

• true → data-only or false (allowed)
• false → true (NOT allowed — parent false wins)

Default SSR

Change the default for all routes in src/start.ts:

import { createStart } from '@tanstack/react-start'

export const startInstance = createStart(() => ({
  defaultSsr: false,
}))

Static Prerendering

Generate static HTML at build time:

// vite.config.ts
tanstackStart({
  prerender: {
    enabled: true,
    crawlLinks: true,
    concurrency: 14,
    failOnError: true,
  },
})

Static routes are auto-discovered. Dynamic routes (e.g. /users/$userId) require crawlLinks or explicit pages config.

SEO and Head Management

Basic Meta Tags

export const Route = createFileRoute('/')({
  head: () => ({
    meta: [
      { title: 'My App - Home' },
      { name: 'description', content: 'Welcome to My App' },
    ],
  }),
})

Dynamic Meta from Loader Data

export const Route = createFileRoute('/posts/$postId')({
  loader: async ({ params }) => fetchPost(params.postId),
  head: ({ loaderData }) => ({
    meta: [
      { title: loaderData.title },
      { name: 'description', content: loaderData.excerpt },
      { property: 'og:title', content: loaderData.title },
      { property: 'og:image', content: loaderData.coverImage },
    ],
  }),
})

Structured Data (JSON-LD)

head: ({ loaderData }) => ({
  scripts: [
    {
      type: 'application/ld+json',
      children: JSON.stringify({
        '@context': 'https://schema.org',
        '@type': 'Article',
        headline: loaderData.title,
      }),
    },
  ],
})

Dynamic Sitemap via Server Route

// src/routes/sitemap[.]xml.ts
export const Route = createFileRoute('/sitemap.xml')({
  server: {
    handlers: {
      GET: async () => {
        const posts = await fetchAllPosts()
        const sitemap = `<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  ${posts.map((p) => `<url><loc>https://myapp.com/posts/${p.id}</loc></url>`).join('')}
</urlset>`
        return new Response(sitemap, {
          headers: { 'Content-Type': 'application/xml' },
        })
      },
    },
  },
})

Common Mistakes

1. HIGH: Missing nodejs_compat flag for Cloudflare Workers

// WRONG — Node.js APIs fail at runtime
{ "compatibility_flags": [] }

// CORRECT
{ "compatibility_flags": ["nodejs_compat"] }

2. MEDIUM: Bun deployment with React 18

Bun-specific deployment only works with React 19. Use Node.js deployment for React 18.

3. MEDIUM: Child route loosening parent SSR config

// Parent sets ssr: false
// WRONG — child cannot upgrade to ssr: true
const parentRoute = createFileRoute('/dashboard')({ ssr: false })
const childRoute = createFileRoute('/dashboard/stats')({
  ssr: true, // IGNORED — parent false wins
})

// CORRECT — children can only be MORE restrictive
const parentRoute = createFileRoute('/dashboard')({ ssr: 'data-only' })
const childRoute = createFileRoute('/dashboard/stats')({
  ssr: false, // OK — more restrictive than parent
})

Cross-References

• start-core/server-routes — API endpoints for sitemaps, robots.txt
• start-core/execution-model — SSR affects where code runs