Cloudflare Workers - Quickstart

Quick Start

This guide is a walk through of using the Serverless Plugin to deploy Cloudflare Workers to a zone already proxied on Cloudflare. domains are not currently supported using Serverless, but you can track our progress on this Github issue.


Node.js v10.X or later. Serverless CLI v1.31.0 or later. You can run npm install -g serverless to install it. you also need our serverless-cloudflare-workers plugin. You can install it in your project with npm install --save serverless-cloudflare-workers.

Create a new service

To create a new service, you can use the cloudflare-workers template. Optionally specify a unique name and an optional path for your service.

# Create a new Serverless Service/Project
$ serverless create --template cloudflare-workers --path new-project
# Change into the newly created directory
$ cd new-project
# Install npm dependencies
$ npm install



To deploy, you will need either the environment variables set or manually input the accountId and zoneId in your serverless.yml according to the zone you wish the Worker(s) to deploy to.

# serverless.yml
  name: hello
    accountId: ${env:CLOUDFLARE_ACCOUNT_ID}
    zoneId: ${env:CLOUDFLARE_ZONE_ID}
      worker: scriptName
      script: filename
      events: ...

Configure the functions according to your specific routing and naming conventions or leave functions as is from what the template generated. When you deploy with the Framework by running serverless deploy, everything in serverless.yml will be deployed at once.

Environment Variables

You will need to set your Global API key from Cloudflare as an environmental variable named CLOUDFLARE_AUTH_KEY, and your Cloudflare account email as an environmental variable named CLOUDFLARE_AUTH_EMAIL. See: How to find your API keys

Environmental variables are variables that live inside your terminal.

For Mac and Linux users, you can set environmental variables like this:


And for Windows (CMD) users, you can set environmental variables like this:


You’ll need to redefine your environmental variables each time you open a new terminal.

Write Code

With the setup all complete we can get to the good stuff of writing code. The path to the file at which you write your Worker is expected to live in what's configured in the serverless.yml under service.functions.someName.script. In this file you can set the fetch event listener and write Worker code in Javascript.


    name: hello
        worker: scriptName
        script: path/filename
        events: ...


addEventListener('fetch', event => {

async function helloWorld(request) {
  return new Response('hello world')

Note: Serverless plugin omits the extension .js in the serverless.yml file when referring to what script to run

Deploy, test and diagnose your service

  1. Deploy the Service

To have the Worker(s) deployed globally run:

serverless deploy

You can use this when you have made changes to your Functions, Events or Resources in serverless.yml or when you simply want to deploy all changes within your Service at the same time. If you've made changes to your routes since last deploying, the Serverless Framework will update them on the server for you.

  1. Deploy the Function

Use this to quickly upload and overwrite your function code, allowing you to develop faster.

serverless deploy -f someName
  1. Invoke the Function

Invokes the Function and returns results.

serverless invoke --function helloWorld

Hello world

Your Function must have the events field populated in order for the serverless tool to know exactly which route to request.

# serverless.yml
  name: foo
  script: bar
    - http:
        # Defines the method used by serverless when the `invoke` command is used. Cloudflare Workers only support GET requests for now
        method: GET


If at any point, you no longer need your service, you can run the following command to remove the Functions, Events and Resources that were created.

serverless remove
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