Migration

You may not always start a new project with Kita, sometimes you will need to migrate an existing project to Kita. This guide will help you to incrementally migrate your project to Kita.

TIP

Migrating projects requires a good understanding of the project structure and the Kita concepts.

Make sure to read all previous documentation to understand how Kita works.

This guide is not a step-by-step guide yet, want to help us to improve this page? Share the technical details of your migration to Kita and we will add it here. Mail us kita@arthur.place or Open a Pull Request.

Migrating from Fastify

Migrating from a already Fastify project to Kita is very simple, you just need to follow the installation guide and add the Kita plugin to your Fastify instance.

import { Kita } from '@kitajs/runtime';
import fastify from 'fastify';

const app = fastify();

// your routes and plugins
app.register(Kita);

app.listen({ port: 1227 });

You can later start to migrate your routes to Kita routes, following the Routing documentation.

Just move each of your routes to their respective path inside src/routes and use the correct I/O types.

DANGER

If you have any existent test suite, it’s expected to continue working as before because Kita does not change the Fastify/server behavior, it just helps you to better declare your routes.

Migrating from Express

Migrating from Express to Kita is a little more complex, but still simple.

Fastify and Express are very different frameworks, so the migration will require a little more work than migrating from Fastify.

Remember: This will be a migration across different frameworks.

First you need to migrate your project from Express to Fastify. While doing so, we recommend following Kita’s guidelines on registering Routes in order to reduce the amount of work needed to migrate to Kita.

TIP

Fastify provides a @fastify/express package to ease this migration.

It should not be used as a long-term solution as it aims to help you have a smooth transition from Express to Fastify, but you should migrate your Express specific code to Fastify over time.

For this migration, there are many useful resources on the internet, such as:

• https://sitepoint.com/express-to-fastify-migrate
• https://blog.appsignal.com/2023/06/28/migrate-your-express-application-to-fastify.html
• https://simonplend.com/learning-fastify-how-to-migrate-your-app-from-express-to-fastify

After migrating from Express to Fastify, you can follow the Migrating from Fastify guide.

Add your project tutorial

If you have migrated a project and want to share your experience, please open a pull request to add your tutorial here.