> ## Documentation Index
> Fetch the complete documentation index at: https://react-native-nfc-kit.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# react-native-nfc-kit

> Modern, typed NFC for React Native and Expo. New Architecture native, Swift and Kotlin, sessions that cannot leak.

NFC for React Native and Expo, built on the Expo Modules API. New Architecture
only, TypeScript throughout, and the asymmetry between iOS and Android visible in
the type system rather than discovered in production.

```ts theme={null}
import { nfc } from 'react-native-nfc-kit';

const message = await nfc.withTag({ tech: ['ndef'], timeoutMs: 20_000 }, async (tag) => {
  if (!tag.is('ndef')) throw new Error('Not an NDEF tag');
  return tag.readNdef();
});
```

<CardGroup cols={2}>
  <Card title="Install it" icon="download" href="/installation">
    Expo or bare React Native, the requirements, and why you need a development build.
  </Card>

  <Card title="Read your first tag" icon="bolt" href="/quickstart">
    From an empty project to a working scan screen, step by step.
  </Card>

  <Card title="Set it up for your use case" icon="wrench" href="/setup/overview">
    One page per case, with both the Expo plugin option and the exact plist and manifest XML.
  </Card>

  <Card title="Coming from nfc-manager" icon="arrow-right-arrow-left" href="/migrating-from-nfc-manager">
    An API equivalence table, and the six differences that change your code.
  </Card>
</CardGroup>

## Two things to know before reading further

<AccordionGroup>
  <Accordion title="A tag carries no technology methods until you narrow it" icon="filter" defaultOpen>
    `tag.is('ndef')` is what makes `readNdef` exist, in the type system and at
    runtime. That is how the platform difference stays visible: on iOS
    `tag.is('mifareClassic')` is always `false`, because CoreNFC cannot reach
    Crypto-1 at any OS version.

    ```ts theme={null}
    if (tag.is('isoDep')) {
      const response = await tag.transceive(command); // ✅ exists here
    }
    await tag.transceive(command); // ❌ does not compile
    ```
  </Accordion>

  <Accordion title="withTag always closes the session" icon="lock" defaultOpen>
    On success, on a throw, on an abort, on a timeout, and when the platform ends
    the session underneath.

    A leaked session keeps the iOS sheet up and holds Android's NFC controller
    exclusively, which is the failure that surfaces two screens later as something
    unrelated.
  </Accordion>
</AccordionGroup>

## What is here

| Entry point                      | What it is                                                       |
| -------------------------------- | ---------------------------------------------------------------- |
| `react-native-nfc-kit`           | Reading and writing tags: sessions, tags, errors                 |
| `react-native-nfc-kit/ndef`      | The NDEF codec. No native dependency, so it runs in Node too     |
| `react-native-nfc-kit/protocols` | ISO 7816, ISO 15693, FeliCa, NTAG/Ultralight, over one primitive |
| `react-native-nfc-kit/hce`       | Card emulation: answer a terminal as though you were a card      |
| `react-native-nfc-kit/vas`       | Read an Apple Wallet pass                                        |
| `react-native-nfc-kit/react`     | Hooks, on a subpath so the core never imports React              |

## What works where

The interesting column is the one that says no. None of this is hidden behind a
method that exists and then throws — `nfc.capabilities` and `tag.is()` tell you at
runtime, and the types tell you before that.

| Feature                      |          iOS          | Android | Web (Chrome) |
| ---------------------------- | :-------------------: | :-----: | :----------: |
| Read and write NDEF          |           ✅           |    ✅    |       ✅      |
| ISO 7816 / ISO-DEP APDUs     |           ✅           |    ✅    |       —      |
| ISO 15693, FeliCa            |           ✅           |    ✅    |       —      |
| NTAG / MIFARE Ultralight     |           ✅           |    ✅    |       —      |
| MIFARE Classic               |           —           | chipset |       —      |
| Raw `NfcA` / `NfcB`          |           —           |    ✅    |       —      |
| Tag-removal callback         |           —           |    ✅    |       —      |
| Background / launch tags     |     system-handled    |    ✅    |       —      |
| Card emulation (HCE)         | entitlement, EEA only |    ✅    |       —      |
| Observe mode, polling frames |           —           | API 35+ |       —      |
| Apple Wallet passes (VAS)    |      entitlement      |    —    |       —      |
| Antenna location             |           —           | API 34+ |       —      |
| Secure NFC status            |           —           | API 29+ |       —      |

<Warning>
  **NFC needs a development build.** It is native code, so Expo Go cannot load it. `npx expo
      run:ios`, `npx expo run:android`, `eas build` and `eas build --local` all produce a build that
  works. See [Installation](/installation).
</Warning>

## Where to go next

<Columns cols={2}>
  <Card title="Sessions" icon="play" href="/concepts/sessions">
    The three ways to get a tag, and which to reach for.
  </Card>

  <Card title="Tags" icon="tag" href="/concepts/tags">
    Narrowing, platform facets, and what a tag can do.
  </Card>

  <Card title="The NDEF codec" icon="code" href="/ndef">
    Building and parsing messages, with or without a device.
  </Card>

  <Card title="Error reference" icon="triangle-exclamation" href="/errors">
    Every `NfcErrorCode`, what causes it, what to do about it.
  </Card>
</Columns>