API Feature Lab

Backend API design, one technique per page. Every page calls a real endpoint of this site's own API, shows the raw request and response, and the code behind it. A sibling of the Vercel, Cloudflare and Motion labs. 8 of 13 built so far.

How it's built

  • Hono serves everything under /api: small, typed, and built on web-standard Request and Response, so it runs on any platform.
  • Zod schemas validate every request and generate the OpenAPI document, so docs and code can't drift.
  • Postgres through Drizzle: Neon in production, PGlite (Postgres in WebAssembly) locally and in tests.
  • Next.js renders these pages; the API is mounted into it with one route file.

Foundations

REST basicsResources, methods and status codes, on a live tasks API.LiveValidation & errorsZod schemas and RFC 9457 Problem Details for every failure.LiveOpenAPI docsA spec generated from the code, rendered as documentation.Live

HTTP semantics

PaginationCursor pagination that stays correct while data changes.LiveETags & caching304 Not Modified, conditional updates and Cache-Control.LiveVersioningEvolving an API without breaking its clients.Live

Auth

API keys & JWTHashed keys, signed tokens and scopes.LiveRate limiting429s with Retry-After and RateLimit headers.Live

Reliability

Idempotency keysRetry a POST safely: the second one changes nothing.Phase 4
WebhooksSigned deliveries with retries and verification.Phase 4
Streaming (SSE)Server-Sent Events for live progress.Phase 4

API styles

REST vs tRPC vs GraphQLThe same data through three API styles.Phase 5

Platform

One API, two platformsThe same Hono app on Vercel and Cloudflare Workers.Phase 6