<!--
{
  "availability" : [
    "iOS: 13.0.0 -",
    "iPadOS: 13.0.0 -",
    "macCatalyst: 13.1.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "CoreNFC",
  "identifier" : "/documentation/CoreNFC/NFCVASReaderSessionDelegate/readerSessionDidBecomeActive(_:)",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
      "Core NFC"
    ],
    "preciseIdentifier" : "c:objc(pl)NFCVASReaderSessionDelegate(im)readerSessionDidBecomeActive:"
  },
  "title" : "readerSessionDidBecomeActive(_:)"
}
-->

# readerSessionDidBecomeActive(_:)

Tells the delegate that the reader session is active.

```
optional func readerSessionDidBecomeActive(_ session: NFCVASReaderSession)
```

## Parameters

`session`

The active reader session. Only one session can be active at a time.

## Discussion

The reader session calls this method after the device begins scanning for new tags.

---

Copyright &copy; 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)