> For the complete documentation index, see [llms.txt](https://docs.payfacto.com/payfacto-knowledge/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.payfacto.com/payfacto-knowledge/canada-doc-center/applications/secure-payment/app-to-app-module-user-guide.md).
# App to App Module User Guide
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{% file src="/files/FH8DQg7zVWtWy2vGwe0R" %}
The Secure Payment App to app module provides payment processing to merchants who use a non-PayFacto terminal payment application. The App to app module is different from the SecurePay, SecureTable, and Gateway modules as there is no communication between the Point of Sale (POS) system and the payment terminal.
Operation of the App to app module more closely resembles the Payment module in standalone mode. The merchant enters the amount of the sale on a third-party terminal application and then the App to app module receives the sale information and processes the sale using the PayFacto servers.
The interface of the third party terminal application used to enter the sale amount can be (and likely is) different from the Secure Payment interface. Any amount for tip, cashback, or fees (where applicable) is added using the Secure Payment interface, as is the prompt to present the card and the authorization server results.
#### What are covered in this guide
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