This step-by-step guide outlines how to update your `connect.yaml` configuration file to automatically generate [API Client credentials](https://docs.commercetools.com/connect/learning-composable-commerce-developer-essentials/authentication-authorization/authentication-and-authorization#api-clients).

# Requirements

Before you begin, ensure you have the following:

- An existing Connector that uses `connect.yaml` for configuration.
- Access to the Composable Commerce API and the necessary credentials.

If you use automatically generated API Client credentials, then the API Client that you used to [create the Deployment](https://docs.commercetools.com/connect/deployments#create-deployment) must have access to the `manage_api_clients:{projectKey}` scope. This helps ensure the necessary permissions for automatically creating credentials are stored within your Project. You must add the scope to the API Client that runs the Deployment; do not add the scope to the `connect.yaml` file of the Connector.

If you don't give access to the `manage_api_clients:{projectKey}` scope, then a `403 access denied` error will occur when you try to deploy a Connector that is configured for automatically generating API Client credentials.

# Update your configuration file

To enable automatic generation of API credentials, update your `connect.yaml` configuration file.

To prevent configuration conflicts, ensure that the `connect.yaml` file does not include any variables that will be automatically generated by the API Client generation feature. These autogenerated variables are provided at runtime and should not be manually defined in the configuration.

The following example shows a `connect.yaml` file with pre-generated Composable Commerce credentials.
With this configuration file, API Client will not be generated automatically.

```yaml title="Example connect.yaml file without automatic API Client generation"
deployAs:
  - name: service_app_name
    applicationType: service
    endpoint: /service
    scripts:
      postDeploy: npm run connector:post-deploy
      preUndeploy: npm run connector:pre-undeploy
    configuration:
      standardConfiguration:
        - key: CTP_PROJECT_KEY
          description: Project key of the commercetools Composable Commerce Project
          required: true
          default: 'default-key'
      securedConfiguration:
        - key: INTEGRATION_API_KEY
          description: API key for the integration
          required: true
        - key: CTP_CLIENT_ID
          description: commercetools Composable Commerce client ID
          required: true
        - key: CTP_CLIENT_SECRET
          description: commercetools Composable Commerce client secret
          required: true
        - key: CTP_SCOPE
          description: commercetools Composable Commerce client scope
  - name: job_app_name
    applicationType: job
    endpoint: /job
    properties:
      schedule: '*/5 * * * *'
    configuration:
      standardConfiguration:
        - key: CTP_PROJECT_KEY
          description: Project key of the commercetools Composable Commerce Project
          required: true
      securedConfiguration:
        - key: INTEGRATION_API_KEY
          description: API key for the integration
          required: true
        - key: CTP_CLIENT_ID
          description: commercetools Composable Commerce client ID
          required: true
        - key: CTP_CLIENT_SECRET
          description: commercetools Composable Commerce client secret
          required: true
        - key: CTP_SCOPE
          description: commercetools Composable Commerce client scope
```

To enable automatic API Client generation, complete the following steps in your `connect.yaml` file:

1. In the `standardConfiguration` object, remove the `CTP_PROJECT_KEY` variable with the Composable Commerce project key: this key will be fetched automatically.
2. In the `securedConfiguration` object, remove the variables with pre-generated Composable Commerce credentials: `CTP_CLIENT_ID`, `CTP_CLIENT_SECRET`, and `CTP_SCOPE`.
3. Add an `inheritAs` object and specify the [scopes](https://docs.commercetools.com/connect/api/scopes) to include for automatically generated API Client credentials as a list in `inheritAs.apiClient.scopes`, for example `manage_payments`, `manage_orders`, `manage_extensions` (only for service application types that use API Extensions), and `manage_subscriptions` (only for event application types that use Subscriptions).

The resulting example `connect.yaml` looks as follows:

```yaml title="Example connect.yaml file with automatic API Client generation"
deployAs:
  - name: service_app_name
    applicationType: service
    endpoint: /service
    scripts:
      postDeploy: npm run connector:post-deploy
      preUndeploy: npm run connector:pre-undeploy
    configuration:
      securedConfiguration:
        - key: INTEGRATION_API_KEY
          description: API key for the integration
          required: true
  - name: job_app_name
    applicationType: job
    endpoint: /job
    properties:
      schedule: '*/5 * * * *'
    configuration:
      securedConfiguration:
        - key: INTEGRATION_API_KEY
          description: API key for the integration
          required: true
inheritAs:
  apiClient:
    scopes:
      - manage_payments
      - manage_orders
      - manage_subscriptions # only for event application types that use Subscriptions
      - manage_extensions # only for service application types that use API Extensions
```

# Variables available in the Connect application

With the automatic generation of API Client credentials, the following environment variables will be available for your Connector:

(a CSV formatted table follows. The first line are the column names.)
Field,Description
`CTP_API_URL`,Composable Commerce API URL.
`CTP_AUTH_URL`,Authentication URL for the Composable Commerce API.
`CTP_CLIENT_ID`,API Client ID for the Connector.
`CTP_PROJECT_KEY`,Composable Commerce Project key.
`CTP_CLIENT_SECRET`,Secret key associated with the Composable Commerce API Client.
`CTP_SCOPE`,List of scopes assigned to the API credentials.