Scaffold a SaaS App

StartupKit Stack is a production-ready starting point for a new product: a blank SaaS application — Next.js 16 on Cloudflare Workers, auth on D1, Stripe billing, transactional email — scaffolded with one command. This is the same flow the CLI's init command performs on your machine.

What Stack isCopy Anchor Link

Stack is StartupKit's free way to start building: a working app with the parts every SaaS needs already wired together, prebuilt auth, analytics, and SEO packages, and an agent skill so your AI agents know how to operate the repo from the first prompt. It's the same kit 01 uses to ship its own products.

Why it's needed — and why it's optionalCopy Anchor Link

Every new product starts the same way: a blank repo and a week of glue work — auth, billing, email, migrations, CI — before a single line of product code gets written. Stack exists to delete that week.

But it's a byproduct, not the point. As 01 shipped product after product across web, mobile, and npm, standardizing on a Cloudflare-native stack became the only sane way to keep moving — Stack is that internal standard, open-sourced.

So: this page is optional. If you already have a stack you like, skip it and bring your own — Research, Launch, and Ads work with whatever you build. Nothing in StartupKit requires the scaffold.

1. Scaffold the projectCopy Anchor Link

npx startupkit init "My SaaS"
cd my-saas

This creates the project folder from 01-studio/startupkit/templates/repo, initializes a fresh git history, runs bun install, and installs the startupkit agent skill so your AI agents know how to operate the stack. A root AGENTS.md (with CLAUDE.md) ships too — the Stack guide: our default agent behaviors (how we work, Linear workflow + etiquette, the git-worktree workflow, SDLC/ADLC) plus a ## StartupKit Stack section for this scaffold. Refresh it with npx startupkit agents --stack; use npx startupkit agents to install the tool-agnostic default guide in any other project.

What's inside:

• Next.js 16 App Router served by a single Cloudflare Worker (OpenNext)
• better-auth — email OTP sign-in + optional Google OAuth, sessions on Cloudflare D1
• Stripe billing — checkout, customer portal, webhook subscription sync
• Transactional email — Cloudflare Email by default; swap Resend or Postmark by config — plus React Email templates
• shadcn-style UI, Tailwind 4, next-intl, vitest, and a tester.army e2e browser suite with a GitHub Actions CI workflow
• Brand kit at /brandkit — paste-ready directory copy, brand assets (logo, OG image, X/LinkedIn/Facebook/YouTube banners, screenshots), and a submission tracker. Public by URL, never indexed

Options: --dir <path> (destination), --repo <user/repo[#branch]> (template source), --no-install (skip bun install).

Prefer plain degit?

npx degit 01-studio/startupkit/templates/repo my-saas

2. Local environmentCopy Anchor Link

cd apps/web
cp .env.example .env.local
cp .dev.vars.example .dev.vars
openssl rand -base64 32

Put the generated value as BETTER_AUTH_SECRET in both files — they must match or sessions will randomly fail.

3. Create the databaseCopy Anchor Link

The template uses Cloudflare D1 (serverless SQLite):

bunx wrangler d1 create startupkit-db

Copy the returned database_id into wrangler.jsonc and wrangler.next-dev.jsonc, then apply the migrations locally:

bun run migrate

4. Run itCopy Anchor Link

bun run dev

• App → http://localhost:3000
• Email preview → http://localhost:3001 (React Email dev server)

Sign up with any email — locally the OTP prints to the dev server log instead of being emailed.

5. Billing & email — your choiceCopy Anchor Link

Billing defaults to Stripe — it's an integration, not a lock-in. More payment providers coming soon.

1. Create a recurring "Pro" product in Stripe (monthly + yearly prices)
2. Set STRIPE_SECRET_KEY, STRIPE_PRICE_PRO_MONTHLY, STRIPE_PRICE_PRO_YEARLY, and STRIPE_WEBHOOK_SECRET in .env.local
3. Point a Stripe webhook at https://<your-domain>/api/stripe/webhook for checkout.session.completed and customer.subscription.*

Upgrade buttons appear on /settings once STRIPE_SECRET_KEY is set.

Email delivery is yours too. Three providers, Cloudflare by default — swap with one env var:

If EMAIL_PROVIDER is unset, a configured key auto-selects that provider; with nothing configured, email prints to the log so local flows still work.

6. DeployCopy Anchor Link

cd apps/web
bunx wrangler secret put BETTER_AUTH_SECRET
bunx wrangler secret put BETTER_AUTH_URL     # https://yourdomain.com
bun run migrate:remote                       # prod D1 migrations
bun run deploy                               # build + upload + shift traffic

Add your domain to the routes block in wrangler.jsonc for a custom domain. Verify a sending domain in Cloudflare Email Service so transactional email delivers (the EMAIL binding is pre-declared).

7. Push to GitHubCopy Anchor Link

gh repo create <org>/<name> --private --source . --push

CI (lint, typecheck, test) runs automatically on every push.

Enable Dependabot security updates — version updates already come from the template's .github/dependabot.yml, but security updates (PRs that fix vulnerable dependencies) are per-repo settings and off by default for private repos:

gh api -X PATCH repos/<org>/<name> \
  -f security_and_analysis[dependabot_alerts]=enabled \
  -f security_and_analysis[dependabot_security_updates]=enabled

8. Make the brand kit yoursCopy Anchor Link

/brandkit ships describing StartupKit itself so it is complete out of the box. Make it yours before you start submitting to directories:

1. apps/web/lib/site.ts — name, URL, one-liner, tagline (≤10 words), short line (≤60 chars), category, socials. This also drives the site's <meta description> and Open Graph / Twitter card tags.
2. apps/web/app/brandkit/page.tsx — rewrite the long-description tiers (Launch, SaaS, B2B review, AI directories, Dev) and the Submit-next rows for your category.
3. Swap apps/web/public/favicon.svg, then regenerate assets with Chrome headless:

bun run brandkit:assets --skip-screenshots                                      # logos, OG image, social banners
BRANDKIT_BASE_URL=http://localhost:3000 bun run brandkit:assets --only=screenshots   # with the app running

bun run test guards the ≤60 / ≤10 constraints and rejects placeholder text.

What's nextCopy Anchor Link

• Read the scaffold's own README.md — full setup reference
• The scaffold's root AGENTS.md — default agent behaviors + the Stack section (Agent Guide, npx startupkit agents --stack)
• CLI Reference — research commands + auth
• MCP Setup — give your agents research tools