# Reference Application
source: https://developer.mastercard.com/payment-initiation-api/documentation/developer-tools/reference-app/index.md

The reference application is a simple Spring Boot Application that shows a typical usage of the Payment Initiation API and how to integrate different operations in the Sandbox environment. You can either re-use or take code references for your implementation.
>
> #### What You Will Learn: {#what-you-will-learn}
>
> * How to use the reference application?
> * How to configure your application for the Sandbox and the Production environments?
> * How to test your reference application?

## Pre-requisites {#pre-requisites}

* Java 17 and above installed.

## Technologies Used {#technologies-used}

* [Spring Boot](https://spring.io/projects/spring-boot)
* [Apache Maven](https://maven.apache.org/)
* [OpenAPI Generator 7.9.x](https://openapi-generator.tech/)

## Download the Reference Application {#download-the-reference-application}

To interact with our reference implementation materials, download the zip file applicable to the following API services:

|      API service       |                                                             Reference application                                                              |
|------------------------|------------------------------------------------------------------------------------------------------------------------------------------------|
| Payment Initiation API | [cdp-payment-initiation.zip](https://static.developer.mastercard.com/content/payment-initiation-api/uploads/cdp-payment-initiation.zip) (95KB) |

* Download and unzip the Java-based reference implementation and follow the setup instructions in the README.MD file.