fastify

name	fastify
description	Fastify 5 — Node-native production HTTP framework. Schema-based validation, plugin encapsulation, hooks pipeline, TS type providers. Use when: fastify, FastifyInstance, fastify.register, fastify-plugin, withTypeProvider, TypeBoxTypeProvider, fastify-type-provider-zod, @fastify/jwt, @fastify/cors, @fastify/helmet, @fastify/rate-limit, @fastify/swagger, @fastify/multipart, addContentTypeParser, setErrorHandler, preHandler, keepAliveTimeout, trustProxy, fastify.inject, graceful shutdown. SKIP: Hono/edge (→hono), Express (→express), NestJS (→nestjs cascade), pure node:http (→nodejs).
stacks	["nodejs-backend","fastify","backend"]
packages	["fastify","@fastify/jwt","@fastify/cors","@fastify/helmet","@fastify/rate-limit","@fastify/swagger","@fastify/type-provider-typebox","@fastify/type-provider-json-schema-to-ts","fastify-plugin","fastify-type-provider-zod","fastify-raw-body"]
tags	["fastify","nodejs","typescript","backend","api","http","validation","plugins"]
manifests	["package.json"]
source	vechkasov-global-skills
risk	high-stakes

🎯 Version Requirements (May 2026)

Primary pins:

• Fastify: 5.x
• Node.js: 24.x (Active LTS)
• TypeScript: 6.0.x

Source of truth: STACK_VERSIONS.md — verified 2026-05-16

Usage

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Use this skill when

• Building or migrating a production HTTP API on Node.js using Fastify 5
• Designing route schemas (querystring / params / body / response) with JSON Schema, TypeBox, or Zod via adapter
• Configuring type providers (withTypeProvider<TypeBoxTypeProvider>()) for end-to-end type safety
• Writing plugins — fastify-plugin for global registration, encapsulation by default
• Using lifecycle hooks: onRequest → preParsing → preValidation → preHandler → handler → preSerialization → onSend → onResponse (+ onError)
• Integrating @fastify/jwt, @fastify/cookie, @fastify/cors, @fastify/helmet, @fastify/rate-limit, @fastify/swagger, @fastify/multipart, @fastify/websocket
• Wiring schema-based response serialization (fast-json-stringify)
• Setting up Pino structured logging (built-in)
• Capturing raw body for webhook HMAC verification (addContentTypeParser with parseAs: 'buffer', or fastify-raw-body)
• Migrating from Fastify 4 to 5 (Node 20+, full JSON Schema, type provider split, removed request.routerPath)
• Testing routes with fastify.inject() against Vitest / node:test

Do not use this skill when

• Task targets Hono / edge runtimes / Cloudflare Workers — use hono
• Task is Express 4/5 middleware migration — use express (cascade) or refactor toward Fastify
• Task is NestJS DI / decorators / modules — use (cascade)