Production-ready Next.js starter kit
Everything between “it works” and “it’s safe to go live,” already done. Auth, payments, security, testing, and a design system. Built for Claude Code from the ground up.
One-time purchase. Lifetime updates.
Next.js 16 · Supabase · Stripe · PostHog · Claude Code
You built a working app with AI tools. Maybe Lovable, maybe Bolt, maybe Claude. It has auth, payments, the works. But as the codebase grows, bugs multiply, context fragments, and every fix creates two new problems. Welcome to the Month 3 Wall.
| What works at first | What breaks at scale |
|---|---|
| Auth and payments in minutes | Edge cases break silently |
| Fast iteration on features | Context fragments, bugs compound |
| Deploy in one click | No tests, no security scanning |
| AI generates code quickly | Generated code ships with unpatched vulnerabilities |
| Polished UI out of the box | Most apps look the same, and new screens drift from your design |
01 · INFRASTRUCTURE
Auth, payments, email, security scanning, CI/CD, and a complete design system. Configured, tested, and working together. Run /setup in Claude Code and start building features, not plumbing.
02 · AI COLLABORATION
Curious about Claude Code but not sure where to start? Sinter gives you a real codebase with a complete methodology already built in. Run /think to explore an idea before writing any code. Run /bootstrap to turn a PRD into a GitHub project board. 27 slash commands, 12 specialized agents, and 19 safety hooks give you spec-driven workflows, structured planning, and verification gates that catch hallucinations before they become bugs.
03 · KNOWLEDGE SYSTEM
375+ documented patterns and decisions that teach Claude Code how your project works. Not generic advice, but your conventions, your edge cases, your architecture. When you solve something with /learn, Claude remembers. When you /reflect, it synthesizes what the codebase has learned and suggests improvements. Run /health periodically to audit the architecture. It catches coupling issues, dead exports, and structural debt that accumulates quietly as you ship.
GETTING STARTED
01
Private GitHub access included with purchase. One command.
$ git clone https://github.com/getsinter/sinter.git02
One command. Claude validates your environment, configures the project, connects your services, and verifies the build. Fully interactive, nothing to guess.
/setup03
Run /think to explore a feature idea. Drop in a PRD and /bootstrap turns it into a roadmap with GitHub issues. Or just tell Claude what to build. Pick whatever matches where you are.
/bootstrapFIG_01 · DESIGN SYSTEM
31 accessible components built on Base UI. Structured tokens, consistent patterns, and an interactive viewer to see it all before changing a thing. Need a new component? Claude builds it in your style.
Create Account
Forms, data display, navigation, overlays. Built on Base UI for accessibility out of the box. Browse them in the interactive viewer.
Alert
Avatar
Badge
Button
Card
Checkbox
DateInput
Dialog
EmptyState
FormField
Input
Label
Link
PasswordInput
Progress
RadioGroup
SectionHeader
Select
Separator
Skeleton
Sonner
Switch
Tabs
Textarea
Toggle
ToggleGroup
Tooltip
WHAT YOU GET
Email/password, magic links, OAuth (Google, GitHub), session management, protected routes, RLS policies
Stripe integration, webhook handling, subscription management, pricing page, customer portal
Resend integration, transactional templates, email verification
Secret scanning, OWASP hardening, OWASP LLM Top 10, CSP headers, CSRF protection, rate limiting
Playwright E2E, Vitest unit tests, AI-assisted test repair, test coverage
30 GitHub Actions workflows, pre-commit hooks, pre-push hooks, automated code review
30+ accessible components, token-based theming, interactive viewer, dark mode
PostHog integration, event tracking, session replay, funnels, user paths
27 slash commands, 12 specialized agents, 19 safety hooks, verification protocol, constitution, PostHog MCP
375+ micro-lessons, heat ranking, pattern guides, /learn, /reflect, and /health commands
Multi-provider support (OpenAI + Anthropic), prompt caching (90% savings), streaming, file uploads, rate limiting
“16 years designing products. Over a year building full-stack with Claude Code, for clients and for my own products. Sinter is everything I learned about going from prototype to production, packaged so you don’t have to learn it the hard way.”
Jonte Edvardson, Founder
PRICING
$249
One-time purchase
One-time purchase. Lifetime updates.
Answered by Claude Code, directly from the codebase.
Have a specific question? Email us →
$249 one-time. Lifetime access to the codebase. Use on unlimited projects.