# Integration and Testing
source: https://developer.mastercard.com/mastercom/documentation/test-cases/index.md

## Ready to Begin Testing? {#ready-to-begin-testing}

Tip: We recommend that you begin testing in the sandbox environment.

Once you have created a project on Mastercard Developers, generated sandbox credentials and received approvals, you can start testing.

### 1. Test cases {#1-test-cases}

Review the Mastercom specific [test cases](https://developer.mastercard.com/mastercom/documentation/test-cases/test-cases/index.md).

### 2. Using our base URLs for testing {#2-using-our-base-urls-for-testing}

* Sandbox
* Production

```Sandbox
https://sandbox.api.mastercard.com/mastercom
```

```Production
https://api.mastercard.com/mastercom
```

## Methods of Testing Sandbox/Production {#methods-of-testing-sandboxproduction-br}

### 1. Reference application {#1-reference-application}

> * Our Spring Boot Reference Application acts as an API client and allows you to integrate different operations.
> * For detailed steps, follow our [Reference Application Page](https://developer.mastercard.com/mastercom/documentation/reference-app/index.md).

### 2. Postman {#2-postman}

> * [Postman](https://www.postman.com/) is an API client that allows developers to test your API's calls in sandbox and production environments without writing any code. [Postman Collections](https://www.postman.com/collection/) makes sharing pre-formed API requests with partners extremely easy, and permits partners to run individual API requests or those within a folder or the entire collection.
> * For detailed steps, follow our [Postman Collections Page](https://developer.mastercard.com/mastercom/documentation/postman-collection/index.md).

### 3. Insomnia {#3-insomnia}

> * [Insomnia](https://insomnia.rest/) is an open-source API client that developers use to quickly and easily send HTTP requests to Mastercard APIs. API Consultancy \& Standards developed an [Insomnia Plugin](https://github.com/Mastercard/insomnia-plugin-mastercard) for handling API authentication.
> * Follow our [Insomnia Tutorial](https://developer.mastercard.com/platform/tutorial/use-insomnia-rest-client-for-mastercard-apis/) to learn how to test the Mastercom OAuth API using Insomnia.

## Next Steps {#next-steps}

* Follow the [Quick Start Guide](https://developer.mastercard.com/mastercom/documentation/quick-start-guide/index.md) for the steps required for moving your Mastercard Developers sandbox project to the Mastercard Test Facility (MTF) and production environments.
* Now that you have an understanding of testing, you can proceed to the [Postman Collections](https://developer.mastercard.com/mastercom/documentation/postman-collection/index.md) section to fork our Postman Collections and begin making calls.
* You can head to our [Reference Application](https://developer.mastercard.com/mastercom/documentation/reference-app/index.md) page to download our Spring Boot Application that shows a typical usage of the Mastercom API.
* To learn more about any error codes you receive, head over to our [Codes and Formats](https://developer.mastercard.com/mastercom/documentation/code-and-formats/index.md) section to learn about the details of all the error codes.