How-to: wallet payloads (registry types)

This is not a wallet library. It receives a UR and hands you bytes. But the biggest UR ecosystem is crypto wallets and air-gapped signers, so here is how the byte layer meets the wallet layer, without this library taking on any wallet dependency.

Where the boundary is

This library gives you DecodedUR: a type string (e.g. crypto-hdkey, crypto-psbt, crypto-account) and cbor, the raw CBOR body as a Uint8Array. It also offers decodeCbor(), which CBOR-decodes that body.
A registry library turns that CBOR into a typed wallet object (an HD key, a PSBT, an account descriptor). That is @ngraveio/ur-registry or @keystonehq/bc-ur-registry, not this package.

Keeping the split means you can receive any UR type, today or future, without waiting on us to add a class for it.

Filter for the type you expect

If you only want extended public keys, reject everything else at the door:

import { URReceiver } from '@nkwib/ur-scanner';

const rx = new URReceiver({
  expectedType: 'crypto-hdkey',
  onError: (e) => { if (e.code === 'UNEXPECTED_TYPE') toast('Scan a crypto-hdkey QR'); },
  onComplete: (ur) => handleHdKey(ur.cbor),
});

expectedType also protects against the classic footgun of a user scanning a PSBT where an account was expected.

Decode the CBOR with a registry lib

// with @keystonehq/bc-ur-registry (illustrative; check the lib's current API)
import { CryptoHDKey } from '@keystonehq/bc-ur-registry';

function handleHdKey(cbor: Uint8Array) {
  const hdKey = CryptoHDKey.fromCBOR(Buffer.from(cbor));
  console.log(hdKey.getBip32Key());
}

The registry library owns the CBOR-to-object mapping and the semantics of each field; this library guarantees only that cbor is exactly the bytes the sender put in the UR.

Common types you might receive

crypto-hdkey, crypto-account, crypto-output, crypto-psbt, crypto-seed, bytes, and vendor extensions. The authoritative lists and decoders live upstream:

Interop reality check

We do not claim hardware-wallet compatibility. Different signers emit slightly different fragment sizes, fps, and (rarely) type spellings. If you verify this library against a Keystone, a Jade, a Passport, or similar, please add a row to the compatibility matrix. That matrix, not this paragraph, is the source of truth for what actually works.