The API of the original LLM Visibility Optimizer, one service among several — a Next.js front end, a Fastify API, a BullMQ worker, Redis — before that whole topology collapsed into a single Nuxt app whose Nitro routes are the API. Fastify's schema-first routes were the part worth keeping in spirit: a request body validated at the edge and a response shaped by contract, which Zod now does here.