Create Contentful Extension is a CLI tool for developing in-app extensions without the hassle of managing build configurations.





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We recommend create-contentful-app over this repo

For new projects, please use the create-contentful-app cli.

Using apps will allow you to use the latest features, and up to date versions of our other open source libraries.

Create Contentful Extension PRs Welcome

Create Contentful Extension is a CLI tool for developing in-app extensions without the hassle of managing build configurations.

If something doesn’t work, please file an issue.

Quick Overview

npx @contentful/create-contentful-extension my-first-extension
cd my-first-extension
npm install
npm run login && npm run configure
npm run start


  • Node 12.13 or higher
  • NPM 6.12.0 and higher

What’s Included?

Your environment will have everything you need to build a modern Contentful UI Extension with React:

  • React, JSX, ES6, TypeScript and all that supported by Parcel
  • Forma 36 - React component library for Contentful design system.
  • A live development server with hot reload.
  • A build script to bundle JS, CSS, and images for production by inlining everything to srcdoc

Despite the fact that we encourage you to use React + Forma36 for building extensions, you can pick any framework and use it as you would use it with Parcel bundler.

Get Started Immediately

You don’t need to install or configure tools like Webpack or Babel.
They are preconfigured and hidden so that you can focus on the code.

We use Parcel bundler under the hood and you can use all assets that are supported there with no additional configuration.

Creating an extension

npx @contentful/create-contentful-extension my-first-extension

It will ask you what type of extension you want to create (read about different types of extensions):

Then npm will install all required development and production dependencies and create a directory called my-first-extension inside the current folder.

Inside that directory, it will generate the initial project structure:

├── node_modules
├── .babelrc
├── .contentfulrc.json
├── .gitignore
├── package.json
├── extension.json
└── src
    ├── index.html
    ├── index.js
    └── index.css

Once the installation is done, you can open your project folder:

cd my-first-extension
# install dependencies
npm install
# login to contentful
npm run login
# select what space and enviroment you'll be using for development and deployment
npm run configure
# starts development server and publishes the extension in a development mode
npm run start

When the development server is up and running open https://app.contentful.com.

Go to Settings -> Extensions to verify that extension is installed in a development mode.

Go to Content model configuration.

Select a field in the Content Type. Navigate to Settings > Appearance of the field. Assign the extension to a field.

Go to the content of this Content Type and enable mixed content at your browser so that development version that is served from your local machine could be rendered within https://app.contentful.com.


npm run start

Starts the development server and deploys the extension in development mode.

The extension will automatically reload if you make changes to the code.

npm run build

Builds the extension for production to the build folder.
It correctly bundles React and all dependencies in production mode and optimizes the build for the best performance.

npm run test

Run jest runner in watch mode. Passes through all flats directly to Jest. If you happen to have a local jest configuration file (i.e: jest.config.js), testing only supports exporting a config object (as opposed to functions).

npm run login

Starts new session with our CLI. As the CLI tool uses our Content Management API, you need to have an CMA access token to use all the commands.

npm run logout

Ends your current session with the CLI tool.

npm run configure

Asks which space and environment you want to use for development and deployment. It saves your answers to local .contentfulrc.json.

Caution: Do not commit .contentfulrc.json to your repository. It contains sensitive information and intended to be used only on your local machine.

npm run deploy

Bundles the extension for production and deploys bundled version to Contentful.

npm run help

Shows help information about create-contentful-extension.


I want to use test environment for during the development. How can I set it up?

Use npm run configure command. It asks what space and environment you'd like to use. The answers are saved in .contentfulrc.json file, located next to package.json.

Caution: Do not commit .contentfulrc.json to your repository. It contains sensitive information and intended to be used only on your local machine.

I want to serve the extension in development mode from a custom port number (not default 1234). Is it possible?

Yes, it's possible. Edit start scripts in package.json file according to the following example:

"start": "contentful-extension-scripts start --port 8000",

I want to serve the extension without creating/updating the extension via the CLI

If you simply want to serve the extension without having the CLI create or update an extension in your space, you can add --serve-only to the start command.

"start": "contentful-extension-scripts start --serve-only",

Available since v0.14.0

I'm using development mode but my extension is not showing up. What's wrong?

In development mode, extension is served from http://localhost:1234, but app.contentful.com is loaded via https protocol which leads the browser to prevent mixed content. While doing development you need to click Load unsafe scripts (Chrome) to enable serving extension from http://localhost.

I'm not the biggest fan of disabling the mixed content setting in browsers. Can I use HTTPS in development mode?

Yes, you can serve your extension using HTTPS. Add --https to start command.

"start": "contentful-extension-scripts start --https",

It uses Parcel HTTPS under the hood , which generates a self-signed certificate, you might have to configure your browser to allow self-signed certificates for localhost.

I generated my extension with create-contentful-extension several months ago but I'd like to use features that became available later. How can I upgrade?

Just update @contentful/contentful-extension-scripts dependency in your package.json to the latest one and check Releases to see if there were any breaking changes. Follow the instructions there.

My extension is bigger than 512Kb. How can I deploy it for production usage?

You can't use Hosted by Contentful (srcdoc) hosted extension if the extension is bigger than 512Kb. But you can serve extension from any server using src property.

Instead of using npm run deploy, add --no-inline to build command:

"build": "contentful-extension-scripts build --no-inline"

It generates minified and production-ready version of your extension. Upload build folder to GitHub pages, Netlify or any other hosting and use Self-hosted (src) option to serve the extension from your own domain.


We'd love to have your helping hand on create-contentful-extension!


Create Contentful Extension is open source software licensed as MIT.

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