fastify-best-practices

Apply plugin-first architecture and encapsulation best practices to Fastify applications.

Updated Jan 31, 2026

Search Tags:#testing #hooks #plugin architecture #fastify #encapsulation #decorators

Ready to run

npx skills add https://github.com/timmywheels/skills --skill fastify-best-practices

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: fastify-best-practices
Source: https://github.com/timmywheels/skills/tree/main/fastify
Command: npx skills add https://github.com/timmywheels/skills --skill fastify-best-practices

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This skill provides guidance on Fastify best practices, focusing on plugin architecture, encapsulation, and composition to help you build maintainable, scalable Node.js backends with Fastify.

Core Features & Use Cases

Encapsulation and plugin-based architecture: every plugin runs in its own isolated context, enabling safe composition and reuse.
Decorators, hooks, and registration patterns: best practices for decorators, lifecycle hooks, and plugin loading orders (including @fastify/autoload usage).
Testing and project structure guidance: how to organize plugins by feature and test them in isolation, with realistic scenarios like building user and admin features.

Quick Start

Create a new Fastify application, implement a small encapsulated plugin with a route (e.g., GET /ping), and register it in the main app to observe encapsulation behavior.

Frequently Asked Questions about fastify-best-practices

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I structure a Fastify application using plugins for encapsulation?▼

Fastify plugin architecture isolates every plugin in its own context to enable safe composition. You organize plugins by feature and register them to achieve a scalable, maintainable project structure with isolated testing.

What is the best way to use decorators and hooks in Fastify?▼

Fastify decorators and lifecycle hooks extend functionality within encapsulated plugins. Following best practices for registration patterns and loading orders ensures decorators and hooks perform optimally without breaking encapsulation.

How does @fastify/autoload handle plugin registration order?▼

@fastify/autoload manages plugin loading orders automatically by scanning directories. It simplifies Fastify project structure by automatically registering encapsulated plugins, ensuring decorators and hooks load correctly for safe composition.

Can I test Fastify plugins in isolation?▼

Yes, you can test Fastify plugins in isolation because every plugin runs in its own encapsulated context. Organizing plugins by feature allows you to test user and admin features independently, ensuring maintainable architecture.

Do I need TypeScript augmentation for Fastify decorators?▼

TypeScript augmentation is required to ensure performance and testability when using Fastify decorators. Augmenting decorators within your plugin architecture provides type safety across encapsulated contexts and ensures scalable composition.

Why should I use fastify-plugin for my application architecture?▼

fastify-plugin breaks encapsulation when needed, allowing decorators and hooks to be shared across the parent Fastify application context. It provides controlled composition, ensuring maintainability while allowing necessary cross-plugin functionality.