An unopinionated SwiftNIO based asynchronous I/O framework, Node.js like.

What's New



Fixes 5.8 compiler warnings, marks some more things inlinable.


A small, unopinionated "don't get into my way" / "I don't wanna wait" asynchronous web framework for Swift. With a strong focus on replicating the Node APIs in Swift. But in a typesafe, and fast way.

Macro is a more capable variant of µExpress. The goal is still to keep a small core, but add some modules and concepts.

Eventually it might evolve into v2 (once backpressure enabled streams are fully working).

The companion MacroExpress package adds Express.js-like middleware processing and functions, as well as templates. MacroLambda has the bits to directly deploy Macro applications on AWS Lambda.


Checkout for people who don't know Node, most things apply to Macro as well.

What does it look like?

The Macro Examples package contains a few examples which all can run straight from the source as swift-sh scripts.

The most basic HTTP server:

#!/usr/bin/swift sh
import Macro // @Macro-swift ~> 0.8.0

  .createServer { req, res in
    res.writeHead(200, [ "Content-Type": "text/html" ])
    res.write("<h1>Hello Client: \(req.url)</h1>")

Macro also provides additional Node-like modules, such as:

  • fs
  • path
  • jsonfile
  • JSON
  • basicAuth
  • querystring

Environment Variables

  • macro.core.numthreads
  • macro.core.iothreads
  • macro.core.retain.debug
  • macro.concat.maxsize
  • macro.streams.debug.rc


This intentionally doesn't support async/await yet as proper streaming would require custom executors. Which are not yet available.


Macro is brought to you by the Always Right Institute and ZeeZide. We like feedback, GitHub stars, cool contract work, presumably any form of praise you can think of.

There is a #microexpress channel on the Slack. Feel free to join!


  • Swift Tools 5.5.0
View More Packages from this Author


Last updated: Thu Sep 28 2023 15:43:12 GMT-0900 (Hawaii-Aleutian Daylight Time)