How to set up TypeScript with Node.js and Express (2025)

Question

Set up a modern, scalable backend using Node.js, Express, and TypeScript with hot-reloading and linting.

Create an initial folder and package. json

mkdir node-express-typescript
cd node-express-typescript
npm init --yes

Installing TypeScript & other dependencies

npm install express mongoose cors mongodb dotenv
npm install  -D typescript ts-node-dev @types/express @types/cors

Generate tsconfig.json

npx tsc --init

Set the rootDir and outDir as src and dist folder

{
  "compilerOptions": {
    "outDir": "./dist"

    // other options remain same
  }
}

Create an Express server with a .ts extension

Create a file name index.ts open it

import express, { Express, Request, Response , Application } from 'express';
import dotenv from 'dotenv';

//For env File
dotenv.config();

const app: Application = express();
const port = process.env.PORT || 8000;

app.get('/', (req: Request, res: Response) => {
  res.send('Welcome to Express & TypeScript Server');
});

app.listen(port, () => {
  console.log(`Server is Fire at http://localhost:${port}`);
});

Watching file changes and build directory

npm install  nodemon

After installing these dev dependencies, update the scripts in the package.json file:

{

  "scripts": {
    "build": "npx tsc",
    "start": "node dist/index.js",
    "dev": "nodemon index.ts"
  }
}

To Run The Code

npm run dev

if everything if perfect you will see the message in console of
Server is Fire at http://localhost:8000

linting setup

npm install --save-dev eslint
npm init @eslint/config@latest
npx eslint . --ext .ts