CoreNFC

Read and write NFC tags on iPhone using the CoreNFC framework. Covers NDEF reader sessions, tag reader sessions, NDEF message construction, entitlements, and background tag reading. Targets Swift 6.3 / iOS 26+.

Contents

• Setup
• NDEF Reader Session
• Tag Reader Session
• Writing NDEF Messages
• NDEF Payload Types
• Background Tag Reading
• Common Mistakes
• Review Checklist
• References

Setup

Project Configuration

1. Add the Near Field Communication Tag Reading capability in Xcode
2. Add NFCReaderUsageDescription to Info.plist with a user-facing reason string
3. Add the com.apple.developer.nfc.readersession.formats entitlement with the tag types your app reads (e.g., NDEF, TAG)
4. For ISO 7816 tags, add supported application identifiers to com.apple.developer.nfc.readersession.iso7816.select-identifiers in Info.plist

Device Requirements

NFC reading requires iPhone 7 or later. Always check for reader session availability before presenting NFC UI.

import CoreNFC

guard NFCNDEFReaderSession.readingAvailable else {
    // Device does not support NFC or feature is restricted
    showUnsupportedMessage()
    return
}

Key Types

NDEF Reader Session

Use NFCNDEFReaderSession to read NDEF-formatted data from tags. This is the simplest path for reading standard tag content like URLs, text, and MIME data.

import CoreNFC

final class NDEFReader: NSObject, NFCNDEFReaderSessionDelegate {
    private var session: NFCNDEFReaderSession?

    func beginScanning() {
        guard NFCNDEFReaderSession.readingAvailable else { return }

        session = NFCNDEFReaderSession(
            delegate: self,
            queue: nil,
            invalidateAfterFirstRead: false
        )
        session?.alertMessage = "Hold your iPhone near an NFC tag."
        session?.begin()
    }

    // MARK: - NFCNDEFReaderSessionDelegate

    func readerSessionDidBecomeActive(_ session: NFCNDEFReaderSession) {
        // Session is scanning
    }

    func readerSession(
        _ session: NFCNDEFReaderSession,
        didDetectNDEFs messages: [NFCNDEFMessage]
    ) {
        for message in messages {
            for record in message.records {
                processRecord(record)
            }
        }
    }

    func readerSession(
        _ session: NFCNDEFReaderSession,
        didInvalidateWithError error: Error
    ) {
        let nfcError = error as? NFCReaderError
        if nfcError?.code != .readerSessionInvalidationErrorFirstNDEFTagRead,
           nfcError?.code != .readerSessionInvalidationErrorUserCanceled {
            print("Session invalidated: \(error.localizedDescription)")
        }
        self.session = nil
    }
}

Reading with Tag Connection

For read-write operations, use the tag-detection delegate method to connect to individual tags:

func readerSession(
    _ session: NFCNDEFReaderSession,
    didDetect tags: [any NFCNDEFTag]
) {
    guard let tag = tags.first else {
        session.restartPolling()
        return
    }

    session.connect(to: tag) { error in
        if let error {
            session.invalidate(errorMessage: "Connection failed: \(error)")
            return
        }

        tag.queryNDEFStatus { status, capacity, error in
            guard error == nil else {
                session.invalidate(errorMessage: "Query failed.")
                return
            }

            switch status {
            case .notSupported:
                session.invalidate(errorMessage: "Tag is not NDEF compliant.")
            case .readOnly:
                tag.readNDEF { message, error in
                    if let message {
                        self.processMessage(message)
                    }
                    session.invalidate()
                }
            case .readWrite:
                tag.readNDEF { message, error in
                    if let message {
                        self.processMessage(message)
                    }
                    session.alertMessage = "Tag read successfully."
                    session.invalidate()
                }
            @unknown default:
                session.invalidate()
            }
        }
    }
}

Tag Reader Session

Use NFCTagReaderSession when you need direct access to the native tag protocol (ISO 7816, ISO 15693, FeliCa, or MIFARE).

final class TagReader: NSObject, NFCTagReaderSessionDelegate {
    private var session: NFCTagReaderSession?

    func beginScanning() {
        session = NFCTagReaderSession(
            pollingOption: [.iso14443, .iso15693],
            delegate: self,
            queue: nil
        )
        session?.alertMessage = "Hold your iPhone near a tag."
        session?.begin()
    }

    func tagReaderSessionDidBecomeActive(
        _ session: NFCTagReaderSession
    ) { }

    func tagReaderSession(
        _ session: NFCTagReaderSession,
        didDetect tags: [NFCTag]
    ) {
        guard let tag 
how to use core-nfc
CursorClaude CodeClineCodexWindsurfGooseGitHub CopilotVS CodeGemini CLIKiloOpencodeKimi CLIRoo ClineAiderContinueZedBolt.newLovablev0Replit AgentSweepSmol DeveloperDevinCavemanAmpAntigravity
How to use core-nfc on Cursor
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1
Prerequisites
Before installing skills in Cursor, ensure your development environment meets these requirements:
›Cursor installed and configured on your development machine
›Node.js version 16.0+ with npm package manager (verify with node --version)
›Active project directory or workspace where you want to add core-nfc
2
Execute installation command
Execute the skills CLI command in your project's root directory to begin installation:
$npx skills add https://github.com/dpearson2699/swift-ios-skills --skill core-nfccopy
The skills CLI fetches core-nfc from GitHub repository dpearson2699/swift-ios-skills and configures it for Cursor.
3
Select Cursor when prompted
The CLI will show a list of available agents. Use arrow keys to navigate and space to select Cursor:
◆ Which agents do you want to install to?
│
│ ── Universal (.agents/skills) ── always included ────
│   • Amp
│   • Antigravity
│   • Cline
│   • Codex
│ ●Cursor(selected)
│   • Cursor
│   • Windsurf
4
Verify installation
Confirm successful installation by checking the skill directory location:
.cursor/skills/core-nfc
Reload or restart Cursor to activate core-nfc. Access the skill through slash commands (e.g., /core-nfc) or your agent's skill management interface.
⚠
Security & Verification Notice
We perform automated surface-level scans (Gen AI Scanner, Socket, Snyk) during installation. These checks detect common vulnerabilities but do not guarantee complete security. Always review skill source code and verify the publisher's reputation before production use.
Skills execute code in your development environment. Always verify the publisher's identity, review recent commits, and test in isolated environments before production deployment.
Additional Resources
›View source code on GitHub›Skills CLI documentation›Learn more about Cursor›What are agent skills?