🔥 The SaaS Starter That Actually Ships

"Stop debugging bleeding-edge tech conflicts. Start building features that matter."

💀 The Bleeding Edge Nightmare

You know this pain:

• ❌ Tailwind v4 breaks your entire design system overnight
• ❌ React 19 concurrent features break your forms
• ❌ Next.js 15 App Router + Turbopack throws cryptic errors
• ❌ Stripe webhooks fail silently in production
• ❌ Supabase SSR hydration mismatches crash your app
• ❌ PostHog + React 19 = duplicate event tracking hell

The brutal reality? Even senior devs spend 3+ months just getting the latest tech stack to play nice together.

⚡️ Latest Tech Stack (Actually Working)

Cutting-Edge Frontend

What's Actually Included

• Next.js 15 with Turbopack (dev server in <200ms)
• React 19 with proper concurrent features
• Tailwind v4 (no more config headaches)
• TypeScript 5 with strict mode
• Supabase SSR (no hydration errors)
• Stripe 18.2 with latest webhook handling
• PostHog analytics (React 19 compatible)
• Vitest testing suite (launching soon)

SSR-First Architecture

✅ Server Components by default
✅ Client components only when needed ('use client')
✅ Zero hydration mismatches
✅ Perfect Lighthouse scores
✅ No "useState during SSR" errors

🛡️ The Integration Hell We Solved

Latest Tech Nightmare Our Battle-Tested Solution Tailwind v4 breaking everything Pre-configured with @tailwindcss/postcss v4 setup React 19 form actions not working Proper useTransition + useActionState implementation Next.js 15 middleware auth errors SSR-compatible auth with @supabase/ssr Stripe webhooks + App Router issues Event handlers in /api/webhooks with proper error boundaries PostHog React 19 conflicts Custom provider with concurrent-safe event tracking Zustand + SSR hydration bugs Store persistence with SSR-safe serialization

🔬 Technical Deep Dive

Why This Stack Actually Works

1. Tailwind v4 Properly Configured

// package.json - The exact versions that work
"@tailwindcss/postcss": "^4",
"tailwindcss": "^4",
"@tailwindcss/typography": "^0.5.16"

2. React 19 + Next.js 15 Harmony

// Server Actions that actually work
export async function createSubscription(formData: FormData) {
  'use server'
  // Proper concurrent features implementation
  const result = await stripe.subscriptions.create({...})
  revalidatePath('/billing')
}

3. SSR-First Supabase Auth

// No more "useUser is not defined" errors
export async function createClient(useServiceRole = false) {
  const cookieStore = await cookies()

  if (useServiceRole) {
    // Service role client bypasses RLS - use for webhook operations
    return createServerClient(
      process.env.NEXT_PUBLIC_SUPABASE_URL!,
      process.env.SUPABASE_SERVICE_ROLE_KEY!, // This bypasses RLS
      {
        cookies: {
          getAll() {
            return cookieStore.getAll()
          },
          setAll(cookiesToSet) {
            try { ...

4. Zero-Config PostHog + React 19

// providers/posthog.tsx - Concurrent-safe analytics
export function PostHogProvider({ children }: PropsWithChildren) {
  // Proper provider setup with React 19 compatibility
}

📦 Complete Production File Structure

Every page and API route you need(all with a simple out of the box setup):

├── app/                          ← Next.js 15 App Router directory
│   ├── account/                  ← User account management section
│   │   ├── billing/              ← Account billing management
│   ├── api/                      ← API routes (server-side endpoints)
│   │   ├── contact/              ← Contact form handler
│   │   ├── stripe/               ← Stripe API endpoints
│   │   ├── webhooks/             ← Webhook handlers (Stripe, etc.)
│   ├── auth/                     ← Authentication flow pages
│   │   ├── confirm/              ← Email confirmation
│   │   ├── error/                ← Auth error handling
│   │   ├── forgot-password/      ← Password reset flow
│   │   ├── login/                ← Login page
│   │   ├── sign-up/              ← Registration
│   │   ├── sign-up-success/      ← Post-registration
│   │   ├── update-password/      ← Password update
│   ├── billing/                  ← Billing & subscription management
│   │   ├── invoices/             ← Invoice history
│   │   ├── payment-methods/      ← Card management
│   │   ├── portal/               ← Stripe customer portal
│   ├── blog/                     ← Blog section
│   │   ├── [slug]/               ← Dynamic blog posts (CMS)
│   │   ├── page.tsx              ← Blog listing page
│   ├── dashboard/                ← User dashboard
│   │   ├── page.tsx              ← Dashboard main page
│   ├── pricing/                  ← Pricing page
│   │   ├── page.tsx              ← Pricing plans display
│   ├── protected/                ← Protected routes example
│   │   ├── layout.tsx            ← Protected section layout
│   │   ├── page.tsx              ← Protected page content
│   ├── studio/                   ← Sanity CMS admin interface
│   │   ├── [[...tool]]/          ← Catch-all route for Sanity Studio
│   ├── success/                  ← Payment success page
│   │   ├── page.tsx              ← Success confirmation UI
│   ├── support/                  ← Support/help page
│   │   ├── page.tsx              ← Support content & contact
│   ├── error.tsx                 ← Global error boundary
│   ├── favicon.ico               ← Site favicon
│   ├── global-error.tsx          ← Root error boundary
│   ├── globals.css               ← Global CSS styles
│   ├── layout.tsx                ← Root layout component
│   ├── loading.tsx               ← Global loading UI
│   ├── not-found.tsx             ← 404 page
│   ├── page.tsx                  ← Homepage component
│   ├── template.tsx              ← Page template wrapper
├── components/                   ← Reusable React components
├── lib/                          ← Utility functions & configurations
├── providers/                    ← React context providers
├── public/                       ← Static assets (images, icons, etc.)
├── sanity/                       ← Sanity CMS schemas & config
├── store/                        ← Zustand state management
├── types/                        ← TypeScript type definitions
├── .env.local                    ← Environment variables (local)
├── .gitignore                    ← Git ignore patterns
├── .prettierignore               ← Prettier ignore patterns
├── components.json               ← Shadcn/ui components config
├── eslint.config.mjs             ← ESLint configuration
├── instrumentation-client.ts     ← Client-side monitoring setup
├── middleware.ts                 ← Next.js middleware (auth & routing)
├── next-env.d.ts                 ← Next.js TypeScript declarations
├── next-sitemap.config.js        ← Auto sitemap generation config
├── next.config.ts                ← Next.js configuration
├── package-lock.json             ← NPM dependency lock file
├── package.json                  ← Project dependencies & scripts
├── postcss.config.mjs            ← PostCSS configuration
├── README.md                     ← Project documentation
├── sanity.cli.ts                 ← Sanity CLI configuration
├── sanity.config.ts              ← Sanity CMS configuration
├── structure.txt                 ← Project structure documentation
├── tsconfig.json                 ← TypeScript configuration

That's 25+ pre-built pages and API routes - everything from auth flows to billing management to CMS integration.

⚠️ The Version Compatibility Matrix

The versions that actually work together:

{
  "next": "15.3.3",           // ← Latest stable
  "react": "^19.0.0",         // ← Release candidate
  "tailwindcss": "^4",        // ← Beta (but stable)
  "@supabase/ssr": "^0.6.1",  // ← SSR-compatible
  "stripe": "^18.2.1",        // ← Latest webhook API
  "posthog-js": "^1.249.5"    // ← React 19 compatible
}

We spent 1000+ hours finding the exact combination that doesn't break.

🎯 Perfect for Developers Who

Want bleeding-edge tech without the bleeding
Need to ship fast with the latest features
Can't afford 3 months debugging version conflicts
Demand SSR-first performance

"I tried upgrading to Next.js 15 + React 19 myself. Unsuccessfully, spent 3 weeks just getting it working. This starter saved me from going insane."
— Alex Rodriguez, Full-Stack Dev

🚀 What You Actually Get

Battle-Tested Integrations

• ✅ Stripe subscriptions with proper webhook handling
• ✅ Supabase auth with SSR (no hydration errors)
• ✅ Sanity CMS (with optional live preview)
• ✅ PostHog analytics (React 19 compatible)
• ✅ Resend emails with React Email templates
• ✅ Tailwind v4 with zero config needed

Pages That Work Out-of-the-Box

Complete Authentication System:

• /auth/login → Magic links + OAuth providers
• /auth/sign-up → User registration with email verification
• /auth/confirm → Email confirmation handling
• /auth/forgot-password → Password reset flow
• /auth/update-password → Secure password updates
• /auth/error → Auth error handling with fallbacks

Full Billing Infrastructure:

• /billing/portal → Stripe Customer Portal integration
• /billing/invoices → Invoice history and downloads
• /billing/payment-methods → Credit card management
• /account/billing → Account-level billing settings
• /success → Post-payment confirmation page
• /pricing → Dynamic pricing from Stripe

Content Management:

• /blog/[slug] → CMS-powered blog posts with SEO
• /studio/[[...tool]] → Full Sanity CMS admin interface
• /dashboard → User analytics and account management
• /support → Help and support pages
• /protected → Example protected route with middleware

API Infrastructure:

• /api/webhooks/* → Stripe webhook handlers (tested)
• /api/stripe/* → Payment processing endpoints
• /api/contact → Contact form submission handler

Performance Optimizations

• ✅ Turbopack dev server (<200ms startup)
• ✅ Server Components by default
• ✅ Optimal bundle sizes
• ✅ Perfect Lighthouse scores
• ✅ Zero client-side JavaScript waste

💰 The Real Cost

DIY "Latest Tech" Approach:

• 80+ hours debugging Next.js 15 + React 19: $8,000
• 40+ hours getting Tailwind v4 working: $4,000
• 60+ hours fixing SSR hydration issues: $6,000
• 30+ hours Stripe + Supabase integration: $3,000
• Total: $21,000+ in dev time

This Starter: $199 ($299 for setup assistance)

Plus your sanity intact.

🔒 What You're Really Buying

The latest tech stack that actually works together:

• ✅ Next.js 15 + React 19 (no conflicts)
• ✅ Tailwind v4 (properly configured)
• ✅ Supabase SSR (zero hydration errors)
• ✅ Stripe webhooks (tested with real events)
• ✅ PostHog analytics (React 19 compatible)
• ✅ TypeScript 5 (strict mode working)
• ✅ Vitest testing suite (coming soon)

This is bleeding-edge tech that doesn't make you bleed.

🚀 Get Started in Minutes

1. git clone [repo-url]
2. cp .env.example .env.local  # Add your API keys
3. npm install
4. npm run dev --turbopack     # <200ms startup
5. Visit /studio to set up CMS
6. Deploy to Vercel (one click)

No version conflicts. No integration hell. No weekend debugging.

Ready to build with the latest tech that actually works?

$199 - Get Instant Access →

30-day money-back guarantee. If you spend more than 4 hours debugging version conflicts, we'll refund you.

⚠️ Warning: If you enjoy spending nights debugging React 19 hydration errors, this probably isn't for you.