# Reference App
source: https://developer.mastercard.com/currency-conversion-calculator/documentation/reference-app/index.md

## Overview {#overview}

A Java reference application is created to guide you through the process of setup and integration with the Mastercard Standard Currency Conversion Calculator API services.

The application is a stand-alone project that does not require any dependency to perform end-to-end testing. The frameworks used to generate the client are Spring Boot, Thymeleaf, and OpenAPI Generator. You can make calls to access daily cardholder currency conversion rates for cross-border payments where the transaction currency differs from the cardholder billing currency.
Note: Existing customers using the Legacy SDK can migrate by downloading the reference application. For step by step instructions please follow the tutorial on [how to integrate using the reference application](https://developer.mastercard.com/currency-conversion-calculator/tutorial/how-to-integrate-using-the-reference-application/index.md).

## Get the Source Code {#get-the-source-code}

Reference Application for Currency Conversion Calculator API is available below:

Download
[currency-conversion-reference-app.zip](https://static.developer.mastercard.com/content/currency-conversion-calculator/uploads/currency-conversion-reference-app.zip) (209KB)
Note: The Reference Application built is for reference purposes only. Your production application does not need to function the same way.