webNfcTapSource

webNfcTapSource(options?: WebNfcTapSourceOptions): TapSource

const WEB_NFC_TAP_SOURCE_PRIORITY = 0

An in-page NFC scan, available on Android Chrome in a secure context. It reads a tap with the device’s own NDEF reader and shapes it like every other tap source, so a core client dispatches to it through captureTap(). defaultTapSources() already includes it; register it directly only when you build the source list yourself. This is a progressive enhancement, not a replacement for the redirect source. iOS has no in-page scanning, and some Android NFC stacks detect a tag but return an empty read, so treat any failure as a cue to fall back to opening the tap link. A scan needs a live user gesture to raise the permission prompt, so run the capture from a control the user pressed, never at page load.

Example

import { EndstatePublicClient } from "@endstate-sdk/core";
import { webNfcTapSource, WebNfcError } from "@endstate-sdk/web";

const client = new EndstatePublicClient({
  publishableKey: "end_pk_live_...",
  tapSources: [webNfcTapSource()],
});

// Inside a user gesture, so the permission prompt can appear.
scanButton.onclick = async () => {
  try {
    const tap = await client.captureTap();
    if (tap) await client.verify(tap);
  } catch (error) {
    if (error instanceof WebNfcError) {
      // Branch on error.reason and fall back to opening the tap link.
    }
  }
};

Parameters

WebNfcTapSourceOptions

Optional configuration.

() => WebNfcWindow | undefined

Test seam that supplies the window the source reads NDEFReader and the permissions API from. Defaults to the page’s own window. Leave it unset in product code.

Returns

A TapSource named web-nfc that a core client registers and dispatches to.

string

required

The source identifier, web-nfc. Pass it to captureTap({ only: [...] }) to target this source, and match it against a captured tap’s source.

number

required

WEB_NFC_TAP_SOURCE_PRIORITY, which is 0.

() => boolean

required

True when the device exposes NDEFReader. Synchronous on purpose, so capture() runs in the same task and the gesture that gates the permission prompt stays live.

(options?) => Promise<TapResult | null>

required

Starts a scan and resolves with the captured tap. Resolves null for a readable tag that is not an Endstate chip, or when no reader is present. Rejects with a WebNfcError when a scan fails in a way the interface should present distinctly.

Priority

WEB_NFC_TAP_SOURCE_PRIORITY is 0, below the redirect source’s 20. A tap already in the URL wins: on a page opened by a tap, the redirect source resolves from the URL before any scan starts. The scanner only runs when no higher-priority source captures.

Web NFC requires Android Chrome on a secure context (HTTPS or localhost). isAvailable() returns false everywhere else, and dispatch moves on to the next source.

Get started

Core SDK

Web SDK

Reader SDK

Example

Parameters

Returns

Priority

See also

​Example

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Example

Parameters

Returns

Priority

See also