Project structure

After coldstart init, you get a Turborepo monorepo. What's inside depends on the platforms and features you selected. Here's a full-stack example (web + API + billing + i18n):

Root

Web app (apps/web/)

Scaffolded by create-next-app, then patched with auth, billing, theming, and i18n.

Key patterns:

• [locale]/ structure for i18n (e.g. /en/dashboard, /fr/dashboard)
• (auth)/ group for public auth pages, (app)/ group for authenticated routes
• useBilling() hook fetches from /billing/status — returns isPremium, tier, credits
• <PremiumGate> wraps content that requires a paid plan — shows upgrade prompt if free

API (apps/api/)

Generated from scratch with Hono, Better Auth, Drizzle, and typed middleware.

Key patterns:

• OpenAPIHono<AppEnv> — typed context, c.get("user") returns { id, email, name }
• Auth routes at /api/auth/* forwarded to Better Auth
• Billing middleware queries userBilling table — no unsafe casts
• Webhooks verify signatures and write real DB operations
• OpenAPI docs at /openapi

Shared packages

pnpm -F @my-saas/db db:generate   # Generate migrations
pnpm -F @my-saas/db db:migrate    # Run migrations
pnpm -F @my-saas/db db:studio     # Open Drizzle Studio

Key files