# Integration and Testing
source: https://developer.mastercard.com/presentment/documentation/integration-and-testing/index.md

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

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

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

### Base URLs for testing: {#base-urls-for-testing}

* Sandbox
* Production

```Sandbox
https://sandbox.api.mastercard.com/loyalty/offers
https://sandbox.api.mastercard.com/loyalty/offers/presentment
```

```Production
https://api.mastercard.com/loyalty/offers
https://api.mastercard.com/loyalty/offers/presentment
```

## 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](https://developer.mastercard.com/presentment/documentation/reference-application/index.md) page.

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

* [Postman Collections](https://www.postman.com/collection/) is an API client that allows developers to test API calls in sandbox and production environments without writing any code. This 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 the [Postman tutorial](https://developer.mastercard.com/platform/tutorial/use-postman-for-mastercard-apis/).

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

* [Insomnia](https://insomnia.rest/) is an open-source API client that developers use to quickly and easily send REST requests to Mastercard APIs. API Consultancy \& Standards developed an [Insomnia Plugin](https://github.com/Mastercard/insomnia-plugin-mastercard) for handling API authentication.
* For detailed steps, follow the [Insomnia tutorial](https://developer.mastercard.com/platform/tutorial/use-insomnia-rest-client-for-mastercard-apis/).

<br />

Download our Insomnia Collection here: [Offers API Insomnia Collection](https://static.developer.mastercard.com/content/presentment/uploads/offers_API_insomnia_collection.zip).

## Next steps {#next-steps}

* Refer to the [User Account Administration Integration and Testing Tutorial](https://developer.mastercard.com/presentment/tutorial/user-account-admin-integration-and-testing/index.md) to create a simple Java application that makes an API call to the User Account Administration service in the Sandbox environment.
* When you are ready to use the API, refer to the [Reference Application](https://developer.mastercard.com/presentment/documentation/reference-application/index.md) section for information on connecting to Offers for Publishers.
* To learn more about any error codes you receive, refer to [Code and Formats](https://developer.mastercard.com/presentment/documentation/code-and-formats/index.md).