> For the complete documentation index, see [llms.txt](https://docs.payments.thalescloud.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.payments.thalescloud.io/nfc-wallet-sdk-ios/implement-nfc-wallet/make-payments/implement-contactless-payment/3.-manage-nfcpresentmentintentassertion.md).

# 3. Manage NFCPresentmentIntentAssertion

The `NFCPresentmentIntentAssertion` object is used to block the default payment application from receiving the "double-click" or "field detect" event. Therefore, for non-default payment applications, it is required to use the `NFCPresentmentIntentAssertion` object in order to perform the contactless payment.

Since iOS 18, you are required to use presentment intent assertion in order to receive the event `ContactlessPaymentSession.Event.posConnected` from TSH Pay SDK, which is based on the `CardSession.Event.ReaderDetected` event. If you do not use the presentment intent assertion, the event that your application received will be `NFCWindowSceneEvent.readerDetected` in `SceneDelegate`.<br>

{% hint style="info" %}
When using the `NFCPresentmentIntentAssertion` object, it is important to manage its lifecycle properly.

* The validity of `NFCPresentmentIntentAssertion` object must be maintained while displaying NFC content, and relying on a local variable that is deallocated upon exiting the function may result in unexpected behavior.
* The presentment intent assertion expires after 15 seconds and after it expires, there is a 15-second cool-down period before you can acquire a new instance. To ensure proper integration with `NFCPresentmentIntentAssertion`, you should use it as a global object in order to maintain a `isValid` check to reuse the existing one.
  {% endhint %}

The following code snippet demonstrates how to use the `NFCPresentmentIntentAssertion` object:

```swift
import CoreNFC

@available(iOS 17.4, *)
class PresentmentIntentWrapper {
    
    static var presentmentIntent: NFCPresentmentIntentAssertion?
    
    static func acquire() async throws {
        presentmentIntent = try await NFCPresentmentIntentAssertion.acquire()
    }
    
    static func isValid() -> Bool {
        guard let presentmentIntent else {
            return false
        }
        return presentmentIntent.isValid
    }
}
```

For more information, refer to [NFCPresentmentIntentAssertion](https://developer.apple.com/documentation/corenfc/nfcpresentmentintentassertion).


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