# Reference App
source: https://developer.mastercard.com/transaction-notifications/documentation/developer-tools/reference-app/index.md

## Overview {#overview}

This reference application provides working code for integrating with Transaction Notifications. Plug in your credentials to run the code and learn how to integrate.

## Prerequisites {#prerequisites}

* Java or Python runtime installed
* Sandbox credentials and signing keys
* Access to Transaction Notifications and [Consent Management \& Enrollment](https://developer.mastercard.com/consent-management/documentation/) APIs in your project

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For more information, see the [Quick Start Guide](https://developer.mastercard.com/transaction-notifications/documentation/quick-start-guide/index.md).

## Download the Reference App {#download-the-reference-app}

Download the sample code:

* Python: [tn-python-ref-app.zip](https://static.developer.mastercard.com/content/transaction-notifications/uploads/tn-python-ref-app.zip) (29KB)
* Java: [tn-java-ref-app.zip](https://static.developer.mastercard.com/content/transaction-notifications/uploads/tn-java-ref-app.zip) (42KB)

## Run the Reference App {#run-the-reference-app}

Follow the instructions in the tutorials to build and run the reference app:

* [Python](https://developer.mastercard.com/transaction-notifications/documentation/developer-tools/reference-app/python-tutorial/index.md)
* [Java](https://developer.mastercard.com/transaction-notifications/documentation/developer-tools/reference-app/java-tutorial/index.md)