> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nearnode.io/llms.txt
> Use this file to discover all available pages before exploring further.

# NFC Writer

> Encode node URLs onto NFC tags directly from your phone — no external hardware required.

The NFC Writer module lets you encode node URLs directly onto NTAG213/215/216 chips from the NearNode console. Write individual tags or batch-encode an entire fleet from your phone.

## Supported Methods

<CardGroup cols={2}>
  <Card title="Web NFC (Mobile)" icon="mobile">
    Use your Android phone's built-in NFC to write tags. Works in Chrome and as an installed PWA.
  </Card>

  <Card title="Desktop Reader" icon="usb">
    Connect an ACR1252U USB reader for high-volume batch writing workflows. *Coming soon.*
  </Card>
</CardGroup>

## Web NFC Quick Start

<Steps>
  <Step title="Open the Writer">
    Navigate to **Writer** in the NearNode dashboard on your Android phone (Chrome or installed PWA).
  </Step>

  <Step title="Select a Node">
    Choose the node you want to write. The URL `nearnode.io/v/{slug}` will be encoded as an NDEF URL record.
  </Step>

  <Step title="Tap to Write">
    Hold the NFC tag to the back of your phone. The writer encodes the URL and automatically verifies the write via read-back.
  </Step>

  <Step title="Lock (Optional)">
    Enable "Lock after write" to make the tag permanently read-only.
  </Step>
</Steps>

<Warning>
  Locking a tag is **permanent and irreversible**. The chip can never be re-written after locking. Only lock tags when you are certain the correct URL has been written and verified.
</Warning>

## Batch Writing

For fleet deployments, the Writer integrates with the [Fleet Management](/features/fleet-management) module:

1. Select a batch from the Fleet page
2. All unwritten nodes appear in a queue
3. Click **Start Batch Write**
4. For each tag placed near the phone: encode → verify → log → next
5. When all nodes are written, batch status transitions to **Deployed**

<Info>
  **Ops Tip:** Install NearNode as a PWA for the best writing experience — standalone mode, no browser chrome, faster launch, and offline queue support.
</Info>

## Offline Support

The NearNode PWA supports offline writes for field deployments without connectivity:

1. Tags are written normally via Web NFC
2. Write logs are queued in IndexedDB
3. Logs sync automatically when connectivity is restored

A background sync indicator shows the number of pending writes.

## Write Log (Audit Trail)

Every write creates an **immutable** audit record. Write logs cannot be edited or deleted — they serve as a tamper-proof chain of custody.

| Field           | Description                                                    |
| --------------- | -------------------------------------------------------------- |
| `hardware_uid`  | The chip's unique serial number (e.g., `04:A2:C8:1A:35:39:80`) |
| `written_url`   | The exact URL written to the tag                               |
| `locked`        | Whether the tag was locked after writing                       |
| `verified`      | Whether a read-back verification was performed                 |
| `writer_method` | `web_nfc`, `desktop_reader`, or `manual`                       |
| `written_by`    | The user who performed the write                               |
| `created_at`    | Timestamp of the write operation                               |

<Tip>
  The `hardware_uid` field enables anti-counterfeit verification. If a scanned chip's UID doesn't match any write log entry, it may be a clone.
</Tip>

## Browser Support

| Browser                | Web NFC Support |
| ---------------------- | --------------- |
| Chrome (Android)       | Yes             |
| Chrome (iOS)           | No              |
| Safari                 | No              |
| Firefox                | No              |
| NearNode PWA (Android) | Yes             |

<Note>
  Web NFC requires HTTPS and a secure context. Both `nearnode.io` and custom domains meet this requirement.
</Note>