Node.js 22 LTS: Native TypeScript, WebSocket Client, Permission Model & More

Node.js 22 is the latest LTS release, and it's packed with features that reduce the need for external tooling. Native TypeScript execution, built-in WebSocket, and the experimental permission model make Node.js more capable than ever.

1. Native TypeScript Execution (--experimental-strip-types)

Node.js can now run TypeScript files directly by stripping type annotations at runtime — no transpilation step needed for simple scripts.

# Run TypeScript directly!
node --experimental-strip-types app.ts

# app.ts
interface User {
  name: string;
  email: string;
}

function greet(user: User): string {
  return `Hello, ${user.name}!`;
}

console.log(greet({ name: "Mortex", email: "info@mortex.com" }));
// Output: Hello, Mortex!

2. Built-in WebSocket Client

No more installing ws for basic WebSocket connections — Node.js 22 includes a standard-compliant WebSocket API.

// No npm install needed!
const ws = new WebSocket('wss://echo.websocket.org');

ws.addEventListener('open', () => {
  console.log('Connected!');
  ws.send('Hello from Node.js 22');
});

ws.addEventListener('message', (event) => {
  console.log('Received:', event.data);
  ws.close();
});

ws.addEventListener('close', () => {
  console.log('Disconnected');
});

3. require(esm) — Use ES Modules in CommonJS

One of the most requested features: you can now require() ES modules synchronously in CommonJS files.

// lib.mjs (ES Module)
export function add(a, b) {
  return a + b;
}

// app.cjs (CommonJS)
const { add } = require('./lib.mjs'); // This now works!
console.log(add(2, 3)); // 5

4. Permission Model

Restrict what your Node.js application can access — file system, network, child processes, and more.

# Only allow reading from ./data and writing to ./output
node --permission \
  --allow-fs-read=./data \
  --allow-fs-write=./output \
  --allow-net=api.example.com \
  app.js

# In code, check permissions
const { permission } = require('node:process');
if (permission.has('fs.read', './secrets')) {
  console.log('Has access to secrets');
} else {
  console.log('Access denied — running in restricted mode');
}

5. Built-in .env File Support

# No more dotenv package!
node --env-file=.env app.js

# Multiple env files
node --env-file=.env --env-file=.env.local app.js

# .env
DATABASE_URL=postgres://localhost:5432/mydb
API_KEY=sk-abc123

6. Native Test Runner (Stable)

import { describe, it, before } from 'node:test';
import assert from 'node:assert/strict';

describe('UserService', () => {
  let service;

  before(() => {
    service = new UserService();
  });

  it('should create a user', async () => {
    const user = await service.create({
      name: 'Test',
      email: 'test@example.com'
    });
    assert.equal(user.name, 'Test');
    assert.ok(user.id);
  });

  it('should validate email format', () => {
    assert.throws(
      () => service.create({ name: 'Test', email: 'invalid' }),
      { message: /Invalid email/ }
    );
  });
});

// Run: node --test