# How to call Mastercard Checkout Solution APIs using Mastercard Postman Collections
source: https://developer.mastercard.com/mastercard-checkout-solutions/tutorial/use-postman-for-mastercard-checkout-services-apis/index.md

## Overview {#overview}

Postman is a platform to build and use APIs. It can be used to write functional tests, integration tests, regression tests, and more. This tutorial will show you how to use Postman collections hosted in the Mastercard workspace on [Postman](https://www.postman.com/mastercard/mastercard-checkout-workspace/overview).

## Prerequisites {#prerequisites}

* Sign up for a new account or log in to your existing postman account.

* Sign up on Mastercard Connect and use **"Mastercard Checkout Solutions - Sandbox"** application to:   

  * [Enroll into a program](https://developer.mastercard.com/mastercard-checkout-solutions/tutorial/onboarding-sandbox/index.md)
  * [Create a project](https://developer.mastercard.com/mastercard-checkout-solutions/tutorial/onboarding-sandbox/step6/index.md) for the program you want to make a call to
  * [Generate necessary keys](https://developer.mastercard.com/mastercard-checkout-solutions/tutorial/key-management/index.md)