SecureStartKit is the Next.js + Supabase + Stripe template for indie hackers who want a real product live this week, on an architecture that doesn't collapse the day someone audits it.
Speed-first templates have an unspoken trade. You ship in a weekend, then spend the next three months patching what the template skipped. Row Level Security off because "we'll add policies later." User IDs read from form payloads. Stripe webhooks accepting whatever JSON shows up at the endpoint. The 2025-2026 wave of indie SaaS hacks (Lovable, the SupaPwn disclosure, 170+ apps with publicly queryable tables) is the bill arriving.
The honest framing: indie hackers don't have a security team. The template has to make the secure path the easy path, because nobody is going to retrofit it later. SecureStartKit is the answer to that constraint, not a different constraint.
Every SecureStartKit project ships with these wired in by default. They're not opt-in features. They're the structural choices that make the common indie SaaS breach classes impossible by construction, not by discipline.
The browser never talks to Supabase directly. Every query runs through a Server Action with the service_role client, after server-side authentication and Zod validation. The architectural choice that makes the whole 2025 Lovable / Supabase RLS breach class structurally impossible.
Read the pattern →Every Server Action runs safeParse at the top. Malformed payloads are rejected at the boundary, before any database write. React Hook Form binds the same schema client-side for instant inline validation, but the server check is the authoritative one.
See the validate-authorize-query pattern →Every table ships with RLS enabled and zero policies. The anon key can do nothing by default. service_role lives behind import "server-only" so it can never enter the browser bundle. A missing policy fails closed, not open.
RLS policies that actually work →The Stripe webhook handler reads the raw body before parsing, verifies the v1 signature with the official SDK, and dedups by event.id against a unique-constraint table. Stripe retries for three days in live mode; without dedup, one purchase becomes ten database writes.
The 5 webhook failure modes →Every Server Action reads the user from getClaims(), never from a userId field on the form. The most common Server Action bug in AI-generated Next.js code (Insecure Direct Object Reference) is structurally absent.
JWT + session management →SecureStartKit is a one-time purchase, not a subscription. Stripe mode `payment`, not `subscription`. The choice itself signals the relationship: you pay once for the foundation, you own what you ship, and the template doesn't extract recurring revenue from a project that hasn't found product-market fit yet.
The indie-hacker math also breaks cleanly: $199 once, deployed in a weekend, is roughly two days of an audit consultant's day-rate. The template runs an architectural audit on itself, every release, and ships the answers as code.
Next.js 16 App Router, Supabase Auth (email/password, OAuth, magic links), Stripe one-time payments with signed webhook handlers, React Email + Resend transactional email, MDX blog + docs system, Server Actions wired with Zod validation across every form, an admin dashboard for the paying-customer side, RLS deny-all schema templates, and the security comparison table that proves the architecture difference. TypeScript end-to-end. Deploy to Vercel, self-host on a VPS, or anywhere Node 24 runs.
Plus a working set of free tools (the SaaS security checklist, the RLS policy generator, the Stripe webhook verifier) that you can use even if you never buy the template. They're how we prove we know what we're talking about before asking for the sale.
You might already have a Lovable, Bolt, or Cursor-generated MVP running. The architecture is probably leaking. The four-phase vibe-coded-to-secure migration playbook walks the audit-to-harden sequence: find every Supabase client instantiation, fix the userId-from-payload patterns, wire signature verification on every webhook, and enable RLS deny-all before adding policies one at a time.
For some prototypes, the migration is faster than the rewrite. For others, starting fresh on SecureStartKit is. The playbook helps you decide which.
One purchase. Lifetime access. The architecture is the demo, and this site runs on it.