nodejs-fastify

Node.js + Fastify

Overview

Fastify is a high-performance Node.js web framework focused on developer experience and low overhead. It uses JSON Schema for request/response validation and serialization.

Project Structure

src/
├── app.ts                   # Fastify instance + plugin registration
├── server.ts                # Entry point (start server)
├── plugins/
│   ├── auth.ts              # Auth decorator/plugin
│   └── database.ts          # DB connection plugin
├── routes/
│   ├── auth/
│   │   ├── index.ts         # Route registration
│   │   └── schema.ts        # JSON schemas
│   └── users/
│       ├── index.ts
│       └── schema.ts
├── services/
│   └── user.service.ts      # Business logic
├── types/
│   └── index.ts             # TypeScript types
└── tests/
    └── routes/
        └── auth.test.ts

Core Patterns

App Setup

import Fastify from 'fastify';

const app = Fastify({
  logger: true,
  ajv: { customOptions: { removeAdditional: 'all' } },
});

// Register plugins
await app.register(import('./plugins/database'));
await app.register(import('./plugins/auth'));

// Register routes
await app.register(import('./routes/auth'), { prefix: '/auth' });
await app.register(import('./routes/users'), { prefix: '/users' });

export default app;

Routes with Schema Validation

import { FastifyPluginAsync } from 'fastify';

const userRoutes: FastifyPluginAsync = async (fastify) => {
  fastify.get('/:id', {
    schema: {
      params: { type: 'object', properties: { id: { type: 'string', format: 'uuid' } }, required: ['id'] },
      response: {
        200: {
          type: 'object',
          properties: {
            id: { type: 'string' },
            email: { type: 'string' },
            name: { type: 'string' },
          },
        },
      },
    },
    preHandler: [fastify.authenticate],
    handler: async (request, reply) => {
      const { id } = request.params as { id: string };
      const user = await fastify.userService.getById(id);
      if (!user) return reply.code(404).send({ error: 'Not found' });
      return user;
    },
  });
};

export default userRoutes;