File System (fs)

The fs module lets Node read, write, and manage files. Use the promise version (fs/promises) with async/await so you don't block the server.

import { readFile, writeFile, appendFile, mkdir } from "fs/promises"

async function main() {
  await writeFile("notes.txt", "Hello\n")
  await appendFile("notes.txt", "World\n")

  const text = await readFile("notes.txt", "utf-8")
  console.log(text)

  await mkdir("logs", { recursive: true })

  // Read JSON
  const data = JSON.parse(await readFile("data.json", "utf-8"))
}

main()