A Sample Cloudflare App
JavaScript Ruby CSS
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CloudFlare Apps

CloudFlare's Apps platform enables developers to create and publish web applications for use by website owners on CloudFlare's network. See the full list.

When you're ready to develop an App, the first step is to sign up as a developer using your CloudFlare account.

This sample repo is an important model for developers. Full documentation is at http://appdev.cloudflare.com

Live Examples

Three live examples of CloudFlare Apps created by outside developers

CloudFlare uses this same method to deliver some new services to its customers. Here are two examples.

App key

Note: the trailing directory in the above examples (/earthhour and /trumpet and /abetterbrowser) is the app key. The app key is unique to your app, and must be approved by CloudFlare.

Building an App

CloudFlare Apps are described with a cloudflare.json file, explained to the site owner with a cloudflare.md file, and are deployed using the CommonJS-compatible module loader cloudflare.js.

To build an app, you might clone this repository, and use it as a template to create your Javascript, app description, and app configuration. When you are done, go to the CloudFlare App Signup Page and submit a description of your app along with a git:// url for the repository.

We will evaluate your app, provide feedback and guidance, and help you publish and promote it to CloudFlare website owners.

Elements of a CloudFlare App repo

This sample app, and the examples cited above, include most of the elements listed below.

  • cloudflare.json (required)
  • cloudflare.md (required)
  • App logo files (required)
  • App JavaScript file (optional)
  • App detail image file(s) (optional)
  • App image file(s) (optional)
  • App CSS file(s) (coming soon; optional)

Descriptions of these elements follow.


The cloudflare.json file contains the packaging information for your application. It includes a path to your main JavaScript file, the definition for your configuration interface, and the location and nature of your non-JS assets. It also contains information on accounts and billing.


Your app detail page is generated by your cloudflare.md file (see A Better Browser app detail page) and the A Better Browser cloudflare.md.

Recommend that you include images, such as screenshots. The max width on the app detail page is 708 pixels. More about images for app detail pages is detailed in the sample cloudflare.md.

App logo files

Suggested directory for your logo files: /APP-KEY/public/images/

Required image file names

  • logo-132.png (132 pixels wide; height not constrained)
  • logo-200.png (200 pixels wide; height not constrained)

You'll define the logo locations in the cloudflare.json file.

App JavaScript file

Your App JavaScript file get deployed on customers' sites when they turn on the App, via cloudflare.js, if your App includes such a script.

App image file(s)

You can add images to your cloudflare.json and have them avaliable on the CloudFlare CDN so you can use them in image tags, etc.

"images" : [

You can then get access to the image at


App image files are versioned on the CDN, so you can request, for example


This will be more useful as versioning features are built that allow certain beta to use versions of the app other than the current version.

More info


cloudflare.js does not currently load CSS files for you. You have two options for reliable CSS in your app.

  • Insert a link tag into the page, and do everything else in a callback when it loads
  • Do all your styling using Javascript.

So far most partners have chosen the second option, and done their styling with JQuery. We are planning to add CSS loading to cloudflare.js so that this can be dealt with for you.


CloudFlare does not require you to provide any tests. This repository contains a sample suite in case you are interested in one way to build tests for cloudflare.js modules.

To run the sample suite, boot up a webserver with the root of this repository as the document root, and open test/suite.html.

Modules of interest

CloudFlare has a set of modules that you can use when writing apps


A dom manipulation library similar to browser methods, but more generic.


Tools for parsing where the page is.


An AJAX wrapper that behaves similarly to jquery.ajax


General information about the site your module is running on.


The website owner sets up an App in their CloudFlare Apps dashboard -- this link only works if signed in to a CloudFlare account, and it will ask you to select which zone (domain) you'd like to configure.

The simplest configuration requires nothing: the App may be turned On or Off, nothing more. Example (from an earlier version): A Better Browser

On-Off only

More configuration is possible. Example: Trumpet.

String example

You can specify an interface in your cloudflare.json for site owners to use to configure your application. The results of that configuration are available in "your_app/config"