The **@fastify/sensible** plugin bundles a set of common utilities that most Fastify applications need—standard HTTP error constructors, response‑helper methods (e.g., `reply.notFound()`, cache‑control helpers, `reply.vary()`), request helpers (`req.forwarded()`, `req.is()`), assertion helpers, and an async‑error wrapper (`fastify.to`). It’s aimed at Fastify developers who want ready‑made, opinion‑free defaults without having to add each utility individually.