​​ Wrangler’s module system

Cloudflare Workers support the ESM module syntax. This means you can use the import/export syntax to add modules to your Worker.

As of Wrangler 2, Wrangler has built-in support for importing modules.

​​ Module formats

Wrangler supports importing modules in the following formats:

• JSX
• TypeScript
• WebAssembly
• HTML files

​​ External packages

Wrangler supports importing modules from external packages.

Here is an example of creating a Worker project that has a dependency on the meaning-of-life package from npm:

First, create the project and install the dependencies.

$ mkdir new-project
$ cd new-project
$ wrangler init -y
$ npm i meaning-of-life

Then, open /src/index.ts and add:

import meaning from "meaning-of-life";

export default {
  async fetch(request: Request): Promise<Response> {
    return new Response(meaning);
  },
};

Now, run wrangler dev and hit b to open the app in your browser.

You should get a blank page with the number 42 on it. The page is served by your Worker which is consuming the meaning-of-life package.