# Fastify Best Practices

Guides development of Fastify Node.js backend servers and REST APIs using TypeScript or...

- Repository: https://github.com/mcollina/skills (1960 stars)
- Category: Testing
- License: MIT
- Last updated: 2026-10-27
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add mcollina/skills --skill fastify-best-practices -g -a claude-code -y`
Codex: `npx skills add mcollina/skills --skill fastify-best-practices -g -a codex -y`
Cursor: `npx skills add mcollina/skills --skill fastify-best-practices -g -a cursor -y`
Gemini CLI: `npx skills add mcollina/skills --skill fastify-best-practices -g -a gemini-cli -y`

## Description

Guides development of Fastify Node.js backend servers and REST APIs using TypeScript or JavaScript. Use when building, configuring, or debugging a Fastify application, including defining routes, implementing plugins, setting up JSON Schema validation, handling errors, optimising performance, managing authentication, configuring CORS and security headers, integrating databases, working with WebSockets, and deploying to production. Covers the full Fastify request lifecycle (hooks, serialization, logging with Pino) and TypeScript integration via strip types. Trigger terms: Fastify, Node.js server, REST API, API routes, backend framework, fastify.config, server.ts, app.ts.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

## When to use

Use this skill when you need to:
- Develop backend applications using Fastify
- Implement Fastify plugins and route handlers
- Get guidance on Fastify architecture and patterns
- Use TypeScript with Fastify (strip types)
- Implement testing with Fastify's inject method
- Configure validation, serialization, and error handling

## Quick Start

A minimal, runnable Fastify server to get started immediately:

```ts
import Fastify from 'fastify'

const app = Fastify({ logger: true })

app.get('/health', async (request, reply) => {
  return { status: 'ok' }
})

const start = async () => {
  await app.listen({ port: 3000, host: '0.0.0.0' })
}
start()
```

## Recommended Reading Order for Common Scenarios

- **New to Fastify?** Start with `plugins.md` → `routes.md` → `schemas.md`
- **Adding authentication:** `plugins.md` → `hooks.md` → `authentication.md`
- **Improving performance:** `schemas.md` → `serialization.md` → `performance.md`
- **Setting up testing:** `routes.md` → `testing.md`
- **Going to production:** `logging.md` → `configuration.md` → `deployment.md`

## How to use

Read individual rule files for detailed explanations and code examples:

The rest: https://github.com/mcollina/skills/blob/HEAD/skills/fastify/SKILL.md