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

How to use

Read individual rule files for detailed explanations and code examples:

rules/plugins.md

- Plugin development and encapsulation

rules/routes.md

- Route organization and handlers

rules/schemas.md

- JSON Schema validation

rules/error-handling.md

- Error handling patterns

rules/hooks.md

- Hooks and request lifecycle

rules/authentication.md

- Authentication and authorization

rules/testing.md

- Testing with inject()

rules/performance.md

- Performance optimization

rules/logging.md

- Logging with Pino

rules/typescript.md

- TypeScript integration

rules/decorators.md

- Decorators and extensions

rules/content-type.md

- Content type parsing

rules/serialization.md

- Response serialization

rules/cors-security.md

- CORS and security headers

rules/websockets.md

- WebSocket support

rules/database.md

- Database integration patterns

rules/configuration.md

- Application configuration

rules/deployment.md

- Production deployment

rules/http-proxy.md

- HTTP proxying and reply.from()

Core Principles

Encapsulation

Fastify's plugin system provides automatic encapsulation

Schema-first

Define schemas for validation and serialization

Performance

Fastify is optimized for speed; use its features correctly

Async/await

All handlers and hooks support async functions

Minimal dependencies

Prefer Fastify's built-in features and official plugins