Introduction

Exis (ExisJS) is a batteries-included backend framework for Node.js. It brings the file-based, convention-over-configuration developer experience of modern frontend meta-frameworks to backend API development: folders and files instead of manual wiring, with the essentials (routing, validation, queues, WebSockets, cron, DI) built in rather than assembled from a dozen separate packages.

Routing is handled by a radix-tree matcher, and the framework supports two ways to define the same routes: Functional (factory functions) and Class-Based / OOP (decorators, in the style of Angular/NestJS). Both compile to the same internal route representation, run through the same middleware pipeline, and can be mixed file-by-file in the same project. Pick whichever fits a given part of your codebase.

Philosophy

Frontend frameworks like Next.js, Remix, and Nuxt improved developer productivity significantly through file-based routing and convention-over-configuration architecture. Good tools exist for Node.js backends too, but assembling them into a coherent application still typically means a lot of manual wiring and architectural boilerplate.

Exis aims to provide that out-of-the-box application architecture for backends: create a folder, get a route; create a gateway.ts, get folder-scoped middleware; import a module, get its providers registered. Job queues, WebSockets, cron scheduling, and schema validation are part of the standard library rather than bring-your-own dependencies. This means a new project starts with a coherent structure instead of a blank index.js and a pile of choices to make first.

Installation

The fastest way to start is the Exis CLI, which scaffolds a new project directory with the core files and a conventional base structure already in place. This is the recommended path for first-time users.

Quick Start

Both paradigms are shown throughout these docs side by side. Pick whichever you're using, or mix them across your project.

Functional API

import { controller, route } from 'exisjs/router'
export default controller({  getUsers: route.get('/', {    handle(req) {      // Return a realistic response structure      return {         data: [          { id: 1, name: 'Alice' },          { id: 2, name: 'Bob' }        ],        total: 2       }    },  }),})

Class-Based (OOP) API

import { Controller, Get, Req } from 'exisjs/decorators'import type { Request } from 'exisjs'
@Controller()export default class UsersController {  @Get('/')  getUsers(@Req() req: Request) {    // Return a realistic response structure    return {       data: [        { id: 1, name: 'Alice' },        { id: 2, name: 'Bob' }      ],      total: 2     }  }}

Save this as src/http/users/route.ts, run exis dev, and GET /users will return your mocked users list.

Adding to an existing project

You can also add Exis to an existing Node.js project instead of scaffolding a new one:

In this case you'll set up the project structure yourself: an exis.config.ts at the project root and a src/http directory for your routes. See Structure for the conventions the framework expects.

What's next

• Installation: CLI setup and project scaffolding in detail.
• Structure: the folder conventions Exis expects and why.
• Routing: how file-based routing, dynamic segments, and gateways work together.