# NFCReaderSessionDelegate A collection of callbacks that provide information about the status of an NFC reader session. ``` @protocol NFCReaderSessionDelegate ``` ## Topics ### Getting the Status of a Reader Session [`- (void) readerSession:(NFCReaderSession *) session didDetectTags:(NSArray<__kindof id> *) tags;`](/documentation/CoreNFC/NFCReaderSessionDelegate/readerSession:didDetectTags:) Provides an array of tags detected by the reader session. [`- (void) readerSession:(NFCReaderSession *) session didInvalidateWithError:(NSError *) error;`](/documentation/CoreNFC/NFCReaderSessionDelegate/readerSession:didInvalidateWithError:) Provides information about the error that invalidated the reader session. [`- (void) readerSessionDidBecomeActive:(NFCReaderSession *) session;`](/documentation/CoreNFC/NFCReaderSessionDelegate/readerSessionDidBecomeActive:) Tells you when radio-frequency polling is enabled and the reader session has become active and is scanning for tags. ## Relationships ### Inherits From [`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)