# Create Customer Client Application
source: https://developer.mastercard.com/account-catalog-services/tutorial/testing-acs-detail-response-api-in-sandbox/step5/index.md

## Create Customer Client Application {#create-customer-client-application}

Account Catalog Services Detail Response API has a reference application working in Springboot / Java.  

For more details, refer to the [Reference App](https://developer.mastercard.com/account-catalog-services/documentation/reference-app/index.md).  

The Reference Application talks about the following points:  

1. How to expose an endpoint.
2. How to decrypt the response send by Mastercard.
3. To use the MTLS setup for this application, we have used a self-signed Certificate Authority. However, DigiCert will be used in the real time.

Tip: You must configure the security for this application by using [step-2](https://developer.mastercard.com/account-catalog-services/tutorial/testing-acs-detail-response-api-in-sandbox/step2/index.md). Note: For more information about test cases, refer to the [testing](https://developer.mastercard.com/account-catalog-services/documentation/testing/index.md).