Next.js SaaS Starter

A working SaaS web app for Next.js 16, built so your AI agent can turn it into your product.

What's inside

• Accounts: sign up, sign in, password reset by email, optional email verification, profile, change password, delete account (Better Auth, sessions in your own database).
• A core resource: "projects" with create, edit, delete and owner-only access. Your agent renames it to your thing: invoices, recipes, courses.
• Plans and billing:
  • Free / Pro / Team plans with limits enforced on the server.
  • Paddle checkout, signed webhooks that record subscriptions, and Paddle's customer portal.
  • A billing simulator, so you can try plans before you have a Paddle account.
• Pages: landing, pricing, terms and privacy stubs, dashboard, billing, settings, an admin page, a 404 page and a health check. Light and dark mode, phone to desktop.
• Postgres with nothing to install: an embedded Postgres (PGlite) for development and tests; any hosted Postgres (Neon, Supabase, your own) in production. Drizzle ORM with SQL migrations.
• Email without an account: in development, emails are printed and kept at /dev/outbox; Resend for production.
• For your agent:
  • a brief (AGENTS.md) and 11 step-by-step recipes
  • one check command: env docs, migrations, types, integration tests, build and browser tests of every page and flow
  • a screenshot tool that signs in as demo users, so it can see its work

Use it with your agent

1. Unzip this folder where you want your project to live.
2. Install Node.js 22 or newer (24 recommended).
3. Open the folder with your agent (Claude Code or similar) and say something like:

This is a SaaS starter template. Read AGENTS.md, then let's turn it into my product: a booking tool for yoga studios called "Flowdesk". Studios manage classes instead of projects.

The agent will ask you a few questions, record your decisions in docs/project.md, and change the app step by step, running the checks after each change.

Run it yourself

npm install
npm run dev          # http://localhost:3000
npm run seed         # demo users: free@ / pro@ / admin@example.com, password "password123"
npm run setup        # once: the browser for the screen tests
npm run check        # everything; ends with CODEPLATE CHECKS: PASS

License

You can use, modify and ship products made from this template, including commercially, with no attribution. You can't resell the template itself. See LICENSE.md. The npm packages it installs keep their own open-source licenses: almost all MIT or Apache-2.0. Two come with Next.js itself: sharp's libvips (LGPL-3.0, for image optimization) and lightningcss (MPL-2.0, for CSS builds). Both are fine to ship in closed-source products as long as you don't modify them.

Made by CodePlate.