# Connection and Integration
source: https://developer.mastercard.com/mastercard-processing-digital/documentation/api-basics-section/connection-and-integration/index.md

There are two ways of integrating with the Mastercard Processing Digital API:

* **API client generated by Mastercard:** Create a customizable API client from the Mastercard Processing OpenAPI Specification (OAS) and let the Mastercard open-source client libraries handle authentication for you. This approach offers more flexibility and is strongly recommended. See the [Generating and Configuring a Mastercard API Client](https://developer.mastercard.com/platform/documentation/security-and-authentication/generating-and-configuring-a-mastercard-api-client/) tutorial for more information.
* **Method of your choice:** Use the REST/HTTP client of your choice and leverage the Mastercard open-source [client libraries](https://developer.mastercard.com/platform/documentation/security-and-authentication/using-oauth-1a-to-access-mastercard-apis/#client-libraries) for signing your requests and dealing with payload encryption. For more information, see [API Reference](https://developer.mastercard.com/mastercard-processing-digital/documentation/api-reference/index.md).

Tip: Refer to the [Build an end-to-end application](https://developer.mastercard.com/mastercard-processing-core/tutorial/build-end-to-end-app/) tutorial of the Core API to help you with building an end-to-end application.