Standard library

The APIs that make sense for CLI tools and microservices — real servers, real files, real crypto — plus the browser-shaped ones that work off-browser.

HTTP server

http.listen is at 100% coverage. It transparently accepts cleartext HTTP/2 (h2c) alongside HTTP/1.1 on the same port.

// The real Node.js shape — this file runs unchanged under Node too.
import http from 'http'

const server = http.createServer((req: IncomingMessage, res: ServerResponse) => {
  res.setHeader('Content-Type', 'text/plain')

  if (req.url === '/hello') {
    res.writeHead(200)
    res.end('hello from a native binary')
    return
  }

  res.writeHead(404)
  res.end('not found: ' + req.url)
})

server.listen(8080)

fetch

fetch, Request, Response and Headers are in. .text()/.json()/.arrayBuffer() are synchronous, and .json() parses a body straight into a declared type.

const r = await fetch('http://127.0.0.1:8765/get')

console.log(r.status)          // 200
console.log(r.ok)              // true

interface Ip { origin: string }

// .json() parses the body straight into a declared type
const data = r.json() as Ip
console.log(data.origin)

File system

fs reads and writes (~93%). Sync and async-shaped variants exist; async runs blocking I/O under the hood. readFileSync/writeFileSync are text-first — use the binary-aware readFileSyncBytes for binary data.

import { readFileSync, writeFileSync } from 'fs'

const config: string = readFileSync('config.json')
writeFileSync('out.txt', 'done\n')

Concurrency & workers

worker_threads and cluster give you real OS threads and processes, each running its own event loop and talking over message channels. Shared memory (SharedArrayBuffer/Atomics) is available too.

Web Crypto

A complete crypto.subtle surface over a selectable backend (OpenSSL or Apple CommonCrypto): digest, HMAC, AES-GCM/CBC, RSA-OAEP/PSS, ECDSA, PBKDF2/HKDF, key formats raw/pkcs8/spki/jwk.

The rest