This package implements an opinionated durable object powered file-system that aims to replicate the exact node fs/promises api and make it available in workers.

npm i cloudflare-fs

Usage:

// worker.js
import { writeFile, DOFS } from "cloudflare-fs";
export { DOFS };
export default {
  fetch: async (request) => {
    await writeFile("/latest-request.txt", request.url, "utf8");
    return new Response("written!");
  },
};

Add to your wrangler.toml

[[durable_objects.bindings]]
name = "DOFS"
class_name = "DOFS"

[[migrations]]
tag = "v1"
new_sqlite_classes = ["DOFS"]

Limitations compared to Node.js fs:

• No streaming APIs - missing createReadStream, createWriteStream
• No sync versions - missing readFileSync, writeFileSync, etc.
• No watch functionality - missing watch, watchFile
• No advanced features - missing link, symlink, readlink, chmod, chown
• No file descriptors - missing open, close, read, write with fd
• Cross-instance operations are simplified and may be slower
• No proper error codes - Node.js fs uses specific error codes like ENOENT, EISDIR
• Limited encoding support - only basic TextEncoder/TextDecoder
• Limited max filesize - capped at the max rowsize of 2MB
• Limited max total disk size - capped at 10GB per disk*

How do disks work?

• every username in paths starting with /Users/{username} becomes its own disk (DO)
• anything else goes to the 'default' disk.