Using Fastify with Next.js for Enhanced Web Performance

Seamless Integration: Using Fastify with Next.js for Enhanced Web Performance

When it comes to building high-performance web applications, selecting the right tools can make all the difference. In this guide, we’ll delve into the synergy between Fastify, a lightning-fast Node.js web framework, and Next.js, a popular React framework for server-rendered applications. By combining these two technologies, you can achieve unparalleled speed and efficiency in your web projects.

Setting the Stage: Integrating Fastify with Next.js

To kickstart the integration of Fastify with Next.js, we need to register the @fastify/nextjs plugin. This plugin enables us to seamlessly use Next.js routes within Fastify. Here’s how to set it up in your project:

ESM (ECMAScript Modules)

// plugin/next.js
import fp from "fastify-plugin";
import nextJs from "@fastify/nextjs";

export default fp(async (fastify, opts) => {
  fastify.register(nextJs);
});

CommonJS

// plugin/next.js
const fp = require("fastify-plugin");
const nextJs = require("@fastify/nextjs");

module.exports = function fp(async (fastify, opts) {
  fastify.register(nextJs);
});

By registering this plugin, you gain access to the @fastify/nextjs plugin decorators across all your Fastify routes.

Rendering Next.js Pages with Fastify

Now that we have Fastify and Next.js working harmoniously, let’s explore how to render Next.js pages within Fastify routes. This is where the true power of this integration shines through. You can seamlessly blend server-rendered Next.js pages into your Fastify application.

ESM

// plugin/root.js

const root = async (fastify, opts) => {
  fastify.get("/", async function (request, reply) {
    return reply.nextRender("/");
  });

  // There is no link between fastify routes and nextjs routes.
  // So you can render any nextjs page on any fastify route.
  // Here the nextjs page pages/index.js is available also at the 
  // /app fastify route
  fastify.get("/app", async function (request, reply) {
    return reply.nextRender("/");
  });
};

export default root;

CommonJS

// plugin/root.js

module.exports = async function root(fastify, opts) {
  fastify.get("/", async function (request, reply) {
    return reply.nextRender("/");
  });

  // There is no link between fastify routes and nextjs routes.
  // So you can render any nextjs page on any fastify route.
  // Here the nextjs page pages/index.js is available also at the 
  // /app fastify route
  fastify.get("/app", async function (request, reply) {
    return reply.nextRender("/");
  });
};

In the provided code, we define Fastify routes that utilize the reply.nextRender() decorator to render Next.js pages. It’s worth noting that there is no strict connection between Fastify routes and Next.js routes. This flexibility allows you to render any Next.js page on any Fastify route, opening up a world of possibilities for building dynamic web applications.

Conclusion

The integration of Fastify with Next.js offers a compelling solution for building high-performance web applications. By combining Fastify’s speed and efficiency with Next.js’s server-rendering capabilities, you can create web applications that load quickly, deliver smooth user experiences, and scale effortlessly.

Whether you’re working with ECMAScript Modules (ESM) or CommonJS, this integration is accessible and adaptable to your project’s needs. So, harness the power of Fastify and Next.js, and unlock the potential for web applications that truly stand out in terms of speed and performance. Your users will thank you for it.