Cursor + Next.js 15 SaaS Starter Kit with Supabase Auth, Stripe Billing & Tailwind UI

Stop losing entire evenings wiring auth, billing, and AI routing. Start shipping a production‑ready SaaS inside Cursor in a single afternoon.

You know the pain: you open a fresh Next.js project and suddenly you’re deep in Supabase docs, Stripe webhooks, broken server actions, and Cursor hallucinating config files you never wrote. You just want a clean SaaS base that deploys without silent auth leaks, multi‑tenant RLS failures, or Stripe subscription errors at 2 a.m.

This starter kit gives you a fully wired Next.js 15 SaaS foundation built specifically for Cursor. Every auth flow, billing flow, AI call, and config file is already connected. You get proven file structures, 12 production‑ready configs, hardened RLS policies, and a working multi‑model AI router so you can focus on your actual product instead of infrastructure puzzles.

What’s Included:
- Supabase Auth with 8 server action patterns for login, signup, magic links, and protected routes
- Hardened RLS policies for multi‑tenant SaaS with safe session handling
- Stripe billing with working usage metering, subscription tiers, and webhook handlers
- A multi‑model AI router supporting OpenAI, Anthropic, Groq, and custom endpoints
- Tailwind UI dashboard shell with sidebar, header, settings pages, and dark mode
- Cursor‑tuned cursor-rules.json and Claude/Copilot instruction files that eliminate hallucinated files
- 12 production configs for local dev, Vercel deploy, Supabase edge functions, and webhook secrets
- Example database schema for teams, invites, roles, and usage logs
- Complete project scaffold using Next.js 15 App Router, server actions, and TypeScript strict mode

This kit is built from patterns used in real paid SaaS products deployed on Vercel and Supabase, tested across hundreds of auth and billing edge cases, and refined inside Cursor to avoid the common model‑confusion traps that break new projects.

Who This Is For:
- Indie hackers who want to launch an AI SaaS this weekend
- Developers who keep fighting Supabase RLS and want a known‑good setup
- Cursor power users who want a project the model can edit without breaking

Who This Is NOT For:
- Developers who want to hand‑roll every integration from scratch
- Hobby projects that don’t need auth, billing, or AI routing

Guarantee: If this doesn’t save you at least 6 hours on setup, reach out for a full refund.

What's Included (14 files)

• cursor-rules.json
• tailwind-dashboard-layout.tsx
• seo-metadata-config.ts
• ai-model-router-openai-claude-groq.ts
• TROUBLESHOOTING.md
• api-rate-limiter-edge.ts
• SETUP-GUIDE.md
• zero-downtime-vercel-deploy.sh
• copilot-instructions.md
• supabase-rls-multi-tenant-policies.sql
• local-env-template.env
• claude-cursor-config.yaml
• stripe-usage-and-subscriptions-setup.ts
• nextjs-supabase-auth-server-actions.ts