# App Requirements

Make sure your Android app meets these requirements before deploying it to Finix-supported PAX terminals.

## Supported Terminals

You can deploy your own apps to the following Finix-supported terminals:

- [PAX A800](/guides/in-person-payments/select-your-device/pax-a800)
- [PAX A920 Pro](/guides/in-person-payments/select-your-device/pax-a920-pro)
- [PAX A35](/guides/in-person-payments/select-your-device/pax-a35)
- [PAX A3700](/guides/in-person-payments/select-your-device/pax-a3700)
- [PAX IM30](/guides/in-person-payments/select-your-device/pax-im30)


See each device page for developer specifications such as the Android version and screen resolution.

## Packaging and Signing

- Build your app as a standard Android APK targeting the Android version of your terminal models.
- Each release must have a unique `versionCode`. Terminals only move forward: to replace a release, publish a higher version.
- Apps are signed and distributed through PAX's app management platform. You don't distribute builds to production terminals directly.


## Platform Differences from Standard Android

PAX terminals are payment devices first, so they differ from consumer Android hardware:

- **No Google Play:** Apps are distributed through PAX's app management platform, not the Play Store. Don't depend on the Play Store for installs or updates.
- **Google Mobile Services:** Services such as Google Maps and Firebase may be limited or unavailable. Verify any Google-dependent functionality on a debug device before you build around it.
- **No production debugging:** Android Debug Bridge (`adb`) is only available on debug devices purchased from PAX. Production terminals can't sideload apps or attach a debugger. For more information, see [Testing Your App](/guides/in-person-payments/deploy-apps-terminals/quickstart#testing-your-app).


## Payment Processing Requirements

- Use the [Finix Device Reader SDK](/guides/in-person-payments/deploy-apps-terminals/quickstart) for all card processing. Your app must not read, store, or transmit card data itself.
- **Remote key injection:** The Finix Device Reader SDK uses key slot 3 in Sandbox and key slot 4 in Production. If your app uses remote key injection, avoid using either of these key slots.


## Questions

If you're unsure whether your app meets these requirements, reach out to your Finix point of contact or email [support@finix.com](mailto:support@finix.com).