fastify

sumak + Fastify

Fastify 5 + JSON schema validation + sumak types.

What it shows

• Layered validation. Fastify's body/params schema catches malformed input at the HTTP boundary; sumak's TypeScript types catch bad queries at compile time. The handler gets fully-typed req.body / req.params that map directly onto .values({...}) and .where(...).
• CHECK constraint round-trip. priceCents is declared with .check("price_cents > 0") on the column. If someone bypasses Fastify's validation (e.g. a stale client), the database still refuses the insert — defense in depth.
• Single builder, many handlers. One sumak() lives at module scope; handlers import it directly. No per-request instantiation, no Fastify decorator magic.

Run

export DATABASE_URL="postgres://postgres:pg@localhost:5432/postgres"
pnpm install
pnpm migrate
pnpm dev

curl -X POST http://localhost:3000/products \
  -H 'content-type: application/json' \
  -d '{"sku":"widget-42","name":"Widget","priceCents":2500}'
curl http://localhost:3000/products/widget-42