Readers and environments

Supported readers

pickReader() picks the best supported driver for the current browser:

Environment	Reader	Notes
Chrome / Edge on desktop	TapTrack Tappy over Web Serial	Preferred transport - works on Windows, macOS, and Linux with stock drivers
Chrome / Edge on desktop	TapTrack Tappy over WebUSB	Automatic fallback; not available on Windows (the OS serial driver owns the device)
Android Chrome	Phone NFC (Web NFC)	No extra hardware; requires HTTPS and a user gesture
iOS	-	iOS has no Web NFC; the OS opens the tap URL directly - see tap redirects

connect() and start() may show a browser device or permission prompt, so call them from a click handler.

Connecting once, not every time

The browser remembers which reader an origin may use, so choosing a device is a one-time authorization rather than part of connecting. The SDK splits the two:

Call	Prompts?	Use it for
`connect({ prompt: false })`	Never	Reconnecting on page load, remount, or SPA navigation. No user gesture needed.
`requestDevice()`	Always	Pairing a reader the first time, or switching to a different one. Must run in a click handler.
`connect()`	Only when nothing is paired	The general-purpose call: silent when it can be, chooser when it must be.

stopScanning() stops delivering taps and leaves the device connected, so the next scan starts without a prompt - use it for component teardown between scans. disconnect() is the explicit release, for when another tab or a desktop application needs the reader. stop() keeps its original “stop and release” meaning and is a deprecated alias for disconnect(). Render the pairing control from the connection state, not from a guess:

type NfcConnectionState =
  | "disconnected"
  | "authorization-required" // no reader paired: show "Connect reader"
  | "connecting"
  | "connected"
  | "error";

reader.onConnectionStateChange?.((state) => render(state));

Only authorization-required is cleared by a user gesture, so a button gated on that state stays hidden once a reader is paired, and a reader unplugged and plugged back in reconnects on its own. Both hold while the browser keeps the grant. When it does not, the state returns to authorization-required and the button comes back - see Troubleshooting.

Package exports

Subpath	Contents	Runs where
`@endstate-sdk/reader`	Readers, `pickReader()`, chip URL parsing	Browser
`@endstate-sdk/reader/react`	`useNfcReader` hook	Browser + React
`@endstate-sdk/reader/ndef`	NDEF URI parsing	Anywhere (pure)
`@endstate-sdk/reader/tcmp`	TapTrack TCMP protocol helpers	Anywhere (pure)

Get started

Core SDK

Reader SDK

Readers and environments

Supported readers

Connecting once, not every time

Package exports

​Supported readers

​Connecting once, not every time

​Package exports

Supported readers

Connecting once, not every time

Package exports