Node.js built-in APIs

Deno Deploy natively supports importing built-in Node.js modules like fs, path, and http through node: specifiers. This allows running code originally written for Node.js without changes in Deno Deploy.

Here is an example of a Node.js HTTP server running on Deno Deploy:

import { createServer } from "node:http";
import process from "node:process";

const server = createServer((req, res) => {
  const message = `Hello from ${process.env.DENO_REGION} at ${new Date()}`;
  res.end(message);
});

server.listen(8080);

You can see this example live here: https://dash.deno.com/playground/node-specifiers

When using node: specifiers, all other features of Deno Deploy are still available. For example, you can use Deno.env to access environment variables even when using Node.js modules. You can also import other ESM modules from external URLs as usual.

The following Node.js modules are available:

assert
assert/strict
async_hooks
buffer
child_process
cluster
console
constants
crypto
dgram
diagnostics_channel
dns
dns/promises
domain
events
fs
fs/promises
http
http2
https
module
net
os
path
path/posix
path/win32
perf_hooks
process
punycode
querystring
readline
stream
stream/consumers
stream/promises
stream/web
string_decoder
sys
timers
timers/promises
tls
tty
url
util
util/types
v8
vm
worker_threads
zlib

The behavior of these modules should be identical to Node.js in most cases. Due to the sandboxing behaviour of Deno Deploy, some features are not available:

Executing binaries with child_process
Spawning workers using worker_threads
Creating contexts and evaluating code with vm

Note: the emulation of Node.js modules is sufficient for most use cases, but it is not yet perfect. If you encounter any issues, please open an issue.