Custom Applications

Start developing Custom Applications for the Merchant Center.

Prerequisites

Before you start development, make sure to have the following:

Yarn PnP is not supported.

Install a starter template

The easiest way to get started is to use one of the starter templates.

We recommend that you create a new Custom Application using the create-mc-app package, which automatically sets up one of the starter templates for you.

npx @commercetools-frontend/create-mc-app@latest \
my-new-custom-application-project \
--template starter
To start with a [TypeScript](https://www.typescriptlang.org/) project, use the `--template=starter-typescript` flag. For more information about developing customizations with TypeScript, see the [Adding TypeScript](/development/adding-typescript) page.

After the installation is complete, follow the instructions to start the development server:

cd my-new-custom-application-project
yarn start

The browser opens a new tab pointing to http://localhost:3001. You are redirected to the login page of the Merchant Center where you need to enter your Merchant Center account credentials.

Once you're authenticated, you are redirected to the local development server and have access to the Project.

If you look at the URL structure of the Merchant Center, you will notice that the URI path starts with the projectKey (the identifier of your commercetools Project) and the entryPointUriPath (the identifier of the Custom Application):

/:projectKey/:entryPointUriPath

Configure the Custom Application

One of the important parts of a Custom Application is the configuration file: custom-application-config.json. We recommend making yourself familiar the Custom Application Config.

By default, the starter template is configured to use the HTTP APIs in the GCP-EU Region. If you plan to run your Custom Application in another environment, you will need to update the cloudIdentifier accordingly. For more information, see our list of cloud identifiers.

User access for local development

To start developing your Custom Application locally, choose a Project belonging to an Organization in which you are a member of the Administrators Team.

As of version 22.5.0, you have the option of assigning granular permissions to teams to enable local development. For more information, see Granular permissions for local development.