JS20

JS20

Documentation

JS20 - Documentation

JS20 - read as "JavaScript 2.0" - is a standard for writing backend applications in TypeScript that automatically generates the frontend SDK. The goal of JS20 is to do anything that is repetitive for you: Auth, ACL, Validation, Sanitation, ORM / queries, and more - so you can focus on only the business logic.

🚀 JS20 has shown to reduce code by up to 90% in real world applications. This reduces bugs, improves maintainability, and speeds up development.

Quick start

✨ Generate a new JS20 project with the command below. This will set up a simple project structure, with an example app & all required dependencies.

npx @js20/core

Features

  • ⚡ Core Building Blocks: Define your app with building blocks - schemas, models, endpoints and actions.
  • 🧬 Database lifecycle: Automatic migrations, queries, and inserts.
  • 🔒 Auth & ACL: Built-in authentication and access control.
  • 🪄 Frontend Generator: Automatically generates a fully type-safe frontend SDK using the same types as backend.
  • 🧩 Flexible & Modular: Plug in any database, web server, or auth provider—no lock-in, fully customizable architecture.
  • 🛡️ Secure by default: Automatic validation and sanitation of user input, CORS & security best practices.
  • 🧠 AI-Ready: Optimized for AI-assisted development—write less code, cut token costs, and reduce bugs.

Run "Hello world" server

import { App } from '@js20/core';

const app = new App();
app.start();

Provides the following output:

Express server is running on port 3000 🚀

Example requests:

- GET /
200 OK
{
    "message": "Running"
}

What's happening here?

  • new App() - Creates a new app, which we can later add a database, endpoints, and more to
  • start() - Starts a new app using express under the hood
  • By default the app only has a single health endpoint at GET /

Beta version

Note: JS20 is currently in beta. We are working on the final pieces to make it fully production-ready. Please try it out and give us feedback, but we don't recommend using it in production yet.

JS20