# Sinter: Full Reference

> Sinter is a production-ready Next.js starter template built for Claude Code. It provides everything between "it works" and "it's safe to go live": authentication, payments, testing, security, CI/CD, a design system, and deep AI collaboration tools. One-time purchase at $249 with all future updates for as long as Sinter is actively developed. Built by Dissonance Labs.

Sinter targets solo founders and small teams (1-3 people) who built a working prototype with AI tools like Lovable, Bolt, or Cursor, and now need to go to production safely. It also serves experienced developers going solo who want production-grade infrastructure without months of setup.

The core tech stack is Next.js 16, React 19, TypeScript 5 (strict mode), Turborepo monorepo, Tailwind CSS 4, shadcn/ui, and Supabase (PostgreSQL + Auth + RLS). Deployed on Vercel.

## What Sinter Includes

### Authentication
- [Documentation](https://getsinter.dev/en/docs)
- Supabase Auth with email/password, magic links, and OAuth providers (Google, GitHub)
- Server-side session management with httpOnly cookies
- Row-Level Security policies at the database level
- Rate limiting on auth endpoints (5 attempts per 15 minutes per IP)
- Swappable adapter pattern supports switching to NextAuth, Clerk, or a custom provider

### Payments
- [Documentation](https://getsinter.dev/en/docs)
- Stripe integration with complete webhook handler
- Covers checkout sessions, subscription lifecycle (created, updated, deleted), invoice payments, trial expiry warnings, refunds, and disputes
- Subscription status tracked in the database
- Pre-built pricing page and customer portal
- Stripe test keys are blocked in production

### Testing Infrastructure
- [Documentation](https://getsinter.dev/en/docs)
- Vitest unit tests with coverage contracts (70% lines/functions, 65% branches)
- Playwright E2E tests with AI-powered planner, generator, and healer agents
- pgTAP database-level RLS testing
- Visual regression testing
- 20+ E2E test files included

### Quality Gates
- [Documentation](https://getsinter.dev/en/docs)
- Pre-commit hooks: formatting, spell-check, secret scanning
- Pre-push hooks: linting, type checking, unit tests
- 29 doctor integrity checks
- 30 CI/CD workflows including security scanning (CodeQL, Gitleaks), accessibility audits (Axe), and AI-powered code review

### Design System
- [Documentation](https://getsinter.dev/en/docs)
- 30+ shadcn/ui components with semantic design tokens
- Dark/light mode with three-tier token architecture (raw values, semantic tokens, component tokens)
- Interactive viewer at /design with component playgrounds
- Automated token validation (contrast, spacing, consistency)
- Custom ESLint rules block hardcoded colors and spacing

### AI Collaboration
- [Documentation](https://getsinter.dev/en/docs)
- 41 skill domains with token savings via lazy loading and progressive disclosure
- 14 specialized agents (security scanner, plan reviewer, test healer, refactor analyzer, and more)
- 19 safety hooks across 10 lifecycle events that block destructive operations and inject context
- Verification protocol to prevent hallucination-driven bugs
- ~65% fewer tokens on average compared to unoptimized codebases

### Self-Improving Documentation
- [Documentation](https://getsinter.dev/en/docs)
- 375+ micro-lessons that compound over time
- 521 documentation files structured for AI consumption
- Searchable knowledge base that grows with your project

### Database Workflow
- [Documentation](https://getsinter.dev/en/docs)
- Migration system with validation
- RLS policy templates with dual-layer validation
- Type generation from schema
- Seed scripts for dev and test environments

### Email
- [Documentation](https://getsinter.dev/en/docs)
- Resend API with React Email components
- Five pre-built templates: welcome, password reset, subscription confirmation, payment failed, trial ending
- i18n support built in

### Internationalization
- [Documentation](https://getsinter.dev/en/docs)
- next-intl v4 with locale-prefixed routing
- Centralized JSON translation files with ESLint enforcement
- Type-safe keys with TypeScript autocomplete

### AI SDK
- [Documentation](https://getsinter.dev/en/docs)
- Vercel AI SDK with Anthropic (Claude) and OpenAI (GPT) support
- Streaming responses and shared Zod schemas

### Security
- Row-Level Security at the database level
- Input validation with Zod schemas on all forms and server-side re-validation
- CSRF protection on API endpoints
- Content Security Policy headers with per-request nonce
- Secret scanning with Gitleaks on every commit
- Rate limiting on auth and AI endpoints
- Error masking to prevent internal detail leaks
- OWASP LLM Top 10 hardening for AI features

## How Sinter Is Different

### vs ShipFast
- [Full comparison](https://getsinter.dev/en/compare)
- Similar price point, different depth
- Sinter is built specifically for Claude Code with 41 skill domains, 14 specialized agents, and 19 safety hooks
- Includes compounding knowledge system (375+ micro-lessons), AI-assisted test repair, and 30 CI/CD workflows with security gates
- ShipFast gives you the basics; Sinter gives you production hardening and an AI development methodology

### vs Enterprise Kits (Makerkit, TurboStarter)
- [Full comparison](https://getsinter.dev/en/compare)
- Enterprise kits offer breadth (multi-tenancy, admin panels)
- Sinter offers depth in AI collaboration, automated quality, and operational readiness
- Right-sized for solo founders, not enterprise teams

### vs AI Prototyping Tools (Lovable, Bolt, v0)
- [Full comparison](https://getsinter.dev/en/compare)
- Great for building your first version
- Sinter is the next step: where you move your prototype when it needs to become a real product
- Not a replacement, but a graduation path

### vs Free Next.js Starters
- A free starter gets you routing and maybe basic auth
- You'll spend weeks adding payment webhooks, writing CI pipelines, configuring security headers, setting up testing, and building a design system
- Sinter has 521 documentation files, 375+ micro-lessons, and 30 CI workflows already working together

## Pricing

- [Pricing page](https://getsinter.dev/en/pricing)
- Solo License: $249 one-time purchase for individual developers
- Team License: $499 one-time purchase for up to 5 seats
- Unlimited projects with both plans
- All future updates for as long as Sinter is actively developed via private GitHub repo
- No recurring fees
- All third-party services (Supabase, Stripe, Resend, PostHog) have free tiers that cover development and early production

## What You Can Build

SaaS apps, dashboards, marketplaces, internal tools, AI products, admin panels. Anything you'd build with Next.js. The stack supports marketing pages, landing pages, and docs sites alongside your app. Ship as a web app, a PWA, or pair with Expo for mobile.

Not a fit for: native iOS/Android apps, WordPress sites, or standalone Shopify storefronts.

## Setup

Clone the repo, install dependencies, and either run /setup in Claude Code (10 minutes, interactive) or pnpm setup-fallback (30-45 minutes, manual). You'll connect Supabase, Stripe, and Resend, set environment variables, and run database migrations.

Prerequisites: Node.js, pnpm, Docker Desktop (for local Supabase), GitHub account, plus accounts with Supabase, Stripe, and Resend.

## Frequently Asked Questions

### Getting Started

**What's included in the purchase?**
Lifetime access to the full Sinter codebase via a private GitHub repo. That includes authentication, payments, transactional email, 30 UI components, 30 CI/CD workflows, 19 safety hooks, 375+ documented micro-lessons, and OWASP LLM Top 10 hardening. Plus all future updates for as long as Sinter is actively developed.

**How long does setup take?**
If you use Claude Code, run /setup and it walks you through everything interactively. That takes about 10 minutes. There's also a manual fallback that takes 30-45 minutes.

**Do I need to know Next.js to use Sinter?**
Basic familiarity helps, but Sinter is designed to work with Claude Code, which understands the codebase deeply. The documentation and micro-lessons mean Claude Code can guide you through Next.js patterns as you build.

### Pricing and License

**Why pay $249 when free starters exist?**
Free starters give you the skeleton. You still need auth edge cases, payment webhooks, testing infrastructure, CI/CD pipelines, security hardening, and a way for your AI tools to understand the codebase. Even a fast, experienced developer would spend months building this from scratch.

**Can I use Sinter for client projects?**
Yes. One purchase, unlimited projects. No per-project licensing.

**What happens if Sinter stops being maintained?**
You keep your code. It's a real codebase you own, not a hosted service.

### Claude Code Integration

**I use Cursor, not Claude Code. Does Sinter still work for me?**
Yes. The infrastructure works with any editor or AI tool. The Claude Code slash commands, agents, and safety hooks are a bonus layer.

**Will Sinter burn through my Claude tokens?**
The opposite. Skills use three-tier progressive disclosure, loading only what the task needs. Code search uses AST patterns instead of reading entire files. The result: ~65% fewer tokens on average compared to an unoptimized codebase.

### Technical

**How does authentication work?**
Supabase Auth with email/password, magic links, and OAuth. Server-side session management with httpOnly cookies. Row-Level Security at the database level. Rate limiting on auth endpoints.

**How does the payment system work?**
Stripe handles everything. Complete webhook handler covering checkout sessions, subscription lifecycle, invoices, refunds, and disputes. Subscription status tracked in the database.

**How is security handled?**
Multiple layers: RLS at database level, Zod validation, CSRF protection, CSP headers, secret scanning, rate limiting, error masking, and OWASP LLM Top 10 hardening.

## Links

- [Website](https://getsinter.dev)
- [Pricing](https://getsinter.dev/en/pricing)
- [Documentation](https://getsinter.dev/en/docs)
- [FAQ](https://getsinter.dev/en/faq)
- [Comparison](https://getsinter.dev/en/compare)
- [License](https://getsinter.dev/en/license)
- [GitHub](https://github.com/getsinter)
- [Dissonance Labs](https://dissonancelabs.eu)