◇ Production-ready building blocks for developers

Skip the plumbing.
Ship the product.

Slipway builds drop-in kits that solve the hard, boring infrastructure — correctly — so you can launch in an afternoon instead of a fortnight. First up: billing that survives production.

Get the Stripe Billing Kit → See what's inside

Next.js 15 · React 19 · TypeScript · Supabase — wire one function and go live.

app/api/stripe/webhook/route.ts

// Every Stripe event — exactly once, even out of order.
export async function POST(req: Request) {
  const event = await verifyStripeSignature(req);

  if (await alreadyProcessed(event.id)) return ok();  // idempotent ✓
  if (await isStale(event)) return ok();             // out-of-order safe ✓

  await applyEntitlements(event);
  await markProcessed(event.id);
  return ok();
}

The flagship kit

Stripe Billing Kit for Next.js 15

Most "add Stripe to Next.js" guides stop at Checkout. Real billing breaks on the parts they skip — webhooks that fire twice, events that arrive out of order, and the App Router changes that broke the old recipes. This kit ships the correct patterns.

◆ Drop-in · fully documented

Everything the tutorials leave out

A complete subscription-billing layer you drop into a Next.js 15 app. Wire one getCurrentUser() and you're live.

Idempotent, out-of-order-safe Stripe webhook — the hard part, solved
Checkout + Customer Portal, wired end to end
getEntitlement() / hasFeature() feature gating
Optional credit billing: idempotent grants + atomic consumption
Supabase schema with race-safe Postgres functions & RLS
Runnable demo app + README, quickstart & security checklist
Pluggable auth — Supabase, Clerk, and NextAuth examples

Next.js 15React 19 TypeScript (strict)Supabase / Postgres Stripe

Launch price

$79 $99

◇ Early bird — $59 for the first 25 buyers

Get the kit

One-time purchase · instant download · free v1.x updates

Why Slipway

Kits you'd actually trust in production

🛠️

Real code, not filler

Hand-built, structurally audited, and designed around the failure modes that only show up under real traffic.

📚

Docs that respect your time

A 10-minute quickstart, an architecture explainer, and a security checklist — so you understand what you ship.

🔄

Kept current

Stripe and Next.js move fast. Kits get free minor updates so your billing layer doesn't rot.

The catalog

More kits on the ramp

Slipway is a growing shelf of production building blocks. The billing kit is first; here's what's queued.

Next up

Claude Code setup kit

An opinionated, tested Claude Code operating system for a specific dev stack.

Planned

Auth starter

The auth edge cases — sessions, roles, org invites — handled cleanly.