This project is marked as deprecated since 2025, today I recommend Hono, blazing fast and build for edge runtimes.

Koaw (Deprecated)

A Koa-like web framework designed for Cloudflare Worker.

If you are using my old package called cf-worker-gateway or worker-scaffold, I suggest switching to this package. Using ctx is more easily to maintain.

English is not my native language; please forgive my typing errors. Improvement about documents is also welcomed!

Installation

Install the core first,

npm install koaw-js
# or
yarn add koaw-js

Usage

Koaw core and KoawRouter all support "Chaining".

Without additional packages, you can use some internal plugins, just like this,

import Koaw, { KoawRouter, cors } from "koaw-js";

addEventListener("fetch", (event) => {
  const app = new Koaw(event);
  const router = new KoawRouter();
  // KoawRouter's handlers
  router.get("/example", (ctx) => {
    ctx.res.body = "hello example";
    ctx.res.status = 200;
    ctx.end(); // The `ctx` must call `.end()` to stop middlewares' execution.
    // If not called at last, the `ctx.res` will be an `unfinished` response.
  });
  // Actually inject middlewares in `Koaw` core
  app.use(cors(true));
  app.use(router.route());

  event.respondWith(app.run());
});

Constructor

const app = new Koaw(event: FetchEvent, options?: object)

The options accept these configurations,

Params	Type	Description
debug	boolean	If set true, errors and debug infomation will be printed

Plugins (Internal)

KoawRouter

The KoawRouter is an middleware which manage handlers with path and method.

The match result is generated from package path-to-regexp, you can make a more complicate use.

const router = new KoawRouter();
router.get("/a/:id", (ctx, match) => {
  // Router's handler has additional param `match` for dynamic route.
  ctx.res.body = match.params.id;
  ctx.res.status = 200;
  ctx.end();
});
// other routes
app.use(router.route());

event.respondWith(app.run());

cors

The function cors is just so simple, you can pass only true, and all CORS configuration will work as default. If you want additional config, you can refer cors in express.js

Transformer

Transformer.responseToCtx

Convert an exist Response to ctx.res

app.use(async (ctx) => {
  let response = await fetch("https://github.com");
  ctx.res = await Transformer.responseToCtx(response);
});

Plugin Packages

Package	Description
-	-

Q & A

Q: Why not continuous maintain @arctome/worker-scaffold ?

A: The reason is very simple. WorkerScaffold is based on Response type detection, every step you need construct a new Response, which needs a lot of code. Also, construct a Response is not an easy way for a Router package, plenty of detection, plenty of clone and re-construction, made the code of core very difficult to maintain. Therefore, I create this package to replace the "old way".

Another reason is that I want to extract the plugins not indispensable. That will allow more plugins developed by community.

Q: Performance ?

A: Not test for now. Will be added soon.