A web framework designed for things to come.

Usage no npm install needed!

<script type="module">
  import quinn from 'https://cdn.skypack.dev/quinn';


nlm-github nlm-node nlm-version


A web framework designed for things to come.[1]

import { createServer } from 'http';
import { createApp, respond } from 'quinn';

const app = createApp(req => respond({ body: 'Hello World!' }));



Request handler

A potentially async function that takes a request and returns a response.

function handler(request) {
  return result;


An http.IncomingMessage. There are no additional properties or magical extension methods.


Either a VirtualResponse[2] or undefined. If it's undefined, the handler was unable to handle the given request. E.g. the handler implements routing logic and no route matched the given url.


The respond function is the primary means to create VirtualResponse instances. It takes one of three possible values:

  • An existing VirtualResponse instance that will be returned unchanged. This ensures that calling respond multiple times is idempotent.
  • A response body (see below).
  • An object with any combination of numeric statusCode, headers object, and/or a body property.

The body can be one of the following:

  • A buffer or Uint8Array.
  • A string.
  • A readable stream.
  • An empty body can be expressed by passing null.
  • A function that takes a request and a response and returns one of the previous types. This variant is called a "lazy body" and can be used to delay serialization or returns bodies that depend on the incoming request as with JSONP responses.


A pass-through stream describing the response that should be returned. While it might have additional utility functions, only the following properties and methods should be relied on:

The behavior of each should match ServerResponse. All headers and the status code should be forwarded when the response is piped to a target. The statusCode by setting the property, the headers by calls to setHeader on the target, one header at a time.

A VirtualResponse can either be piped to a target stream or forwarded using response.forwardTo(req, res). Lazy bodies are only supported when using forwardTo. When using forwardTo, it will return a promise that resolves once the response has been successfully written.

Combining Quinn

With Express

import express from 'express';
import { createApp as quinn, respond } from 'quinn/express';

const app = express();
app.get('/quinn-route', quinn(req => respond({ body: 'Hello World!' })));


Similar Libraries

Most of these are based on JSGI. Which would make sense if node wouldn't include an http server.

[1] In other words: an experimental mess.

[2] Because buzz word.