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Coin-level QR codes

ur:crypto-accountur:crypto-hdkeyur:crypto-multi-accountsplain address

The coin-level QR codes use the same UR types as other QR signers (they follow the Blockchain Commons and Keystone registries), so a wallet that already imports Keystone-style accounts can usually read them unchanged. In the app: Connect › Coin Level, then pick a chain.

ChainDefault exportAlternative
Bitcoinur:crypto-account with one account xpub (choose Native SegWit, Taproot, Nested SegWit or Legacy)Plain address; multisig cosigner xpub
EVMur:crypto-hdkey, the m/44'/60'/0' account nodePlain address (index 0)
Solanaur:crypto-multi-accounts with one preset keyPlain address
TRONPlain address of any index m/44'/195'/0'/0/i—

Each QR code has a Payload section in the app showing the decoded content, exactly as in the JSON views on this page. The integer CBOR keys are shown with their registry field names; fingerprints are 32-bit integers (1942346250 = 0x73C5DA0A).

Bitcoin: crypto-account​

crypto-account = {
  1: master-fingerprint (uint32),
  2: [ output-descriptor ]          ; exactly one
}
output-descriptor = script tag(s) wrapping  303(crypto-hdkey)
Address typeAccount pathDescriptor tagsScript
Native SegWitm/84'/0'/0'404(303(key))wpkh
Taprootm/86'/0'/0'409(303(key))tr (BIP86)
Nested SegWitm/49'/0'/0'400(404(303(key)))sh(wpkh)
Legacym/44'/0'/0'403(303(key))pkh

The crypto-hdkey inside carries the account public key (33 bytes), chain code, origin path with source fingerprint and depth, parent fingerprint, and the name BitTool Signer. Receive addresses are …/0/i, change addresses …/1/i.

Two details if you parse it yourself:

  • The output descriptor is written the way Keystone and Sparrow write it, without the 308(crypto-output) wrapper from BCR-2020-015.
  • Taproot uses tag 409 (tr) with the untweaked internal key; apply the BIP86 tweak when deriving addresses. Older registry libraries do not know tag 409 and silently drop it (the sample decoder below reads the tags directly for this reason).
m/84'/0'/0' · crypto-accountFirst receive address: bc1qcr8te4kr609gcawutmrza0j4xv80jy8z306fyu
UR:CRYPTO-ACCOUNT/OEADCYJKSKTNBKAOLYTAADMWTAADDLPDAOWKAXHDCLAOJOKNIDZCPSSAJTPTRPFRCECFKKAMYKJTVTCSBTBDTKCFIYVYOETNEEYKWFNBNYNDAHTAADEHNBAMTAADDYOTADLNCSGHYKAEYKAEYKAOCYJKSKTNBKAXAXAAHDCXGEGUNBPYCLRHUOMDLNNSGLMOOYHSCFGLAXRTWSFHYKADGESWMOWKEOSSKOGHMHZTAYCYKBWFDNUYASJTFWINJYGHJLJLJZCXGUINIOJTIHJPBKKSCAFWINJYGHJLJLJZCXGUINIOJTIHJPCXJOKPIDJZINIACXHSIAIAJLKPJTJYDPCXPECF
Decoded payload
{
  "master-fingerprint": 1942346250,
  "output-descriptors": [
    {
      "witness-public-key-hash": {
        "crypto-hdkey": {
          "is-private": false,
          "key-data": "02707a62fdacc26ea9b63b1c197906f56ee0180d0bcf1966e1a2da34f5f3a09a9b",
          "use-info": {
            "crypto-coin-info": {}
          },
          "origin": {
            "crypto-keypath": {
              "components": [
                84,
                true,
                0,
                true,
                0,
                true
              ],
              "source-fingerprint": 1942346250,
              "depth": 3
            }
          },
          "chain-code": "4a53a0ab21b9dc95869c4e92a161194e03c0ef3ff5014ac692f433c4765490fc",
          "parent-fingerprint": 2129865691,
          "name": "BitTool Signer",
          "note": "BitTool Signer public account"
        }
      }
    }
  ]
}
QR text
UR:CRYPTO-ACCOUNT/OEADCYJKSKTNBKAOLYTAADMWTAADDLPDAOWKAXHDCLAOJOKNIDZCPSSAJTPTRPFRCECFKKAMYKJTVTCSBTBDTKCFIYVYOETNEEYKWFNBNYNDAHTAADEHNBAMTAADDYOTADLNCSGHYKAEYKAEYKAOCYJKSKTNBKAXAXAAHDCXGEGUNBPYCLRHUOMDLNNSGLMOOYHSCFGLAXRTWSFHYKADGESWMOWKEOSSKOGHMHZTAYCYKBWFDNUYASJTFWINJYGHJLJLJZCXGUINIOJTIHJPBKKSCAFWINJYGHJLJLJZCXGUINIOJTIHJPCXJOKPIDJZINIACXHSIAIAJLKPJTJYDPCXPECF

Bitcoin multisig cosigner​

For multisig wallets BitTool Signer exports one cosigner key in crypto-account, at the BIP48 paths:

TypeAccount pathDescriptor tags
P2WSHm/48'/0'/0'/2'401(303(key)) (wsh)
P2SH-P2WSHm/48'/0'/0'/1'400(401(303(key))) (sh(wsh))

This is one participant only. It carries no threshold, no other cosigners and no final address. Your wallet builds the full policy (for example a sorted 2-of-3 wsh(sortedmulti(…))) from all cosigners' exports.

P2WSH cosigner test vector
Decoded payload
{
  "master-fingerprint": 1942346250,
  "output-descriptors": [
    {
      "witness-script-hash": {
        "crypto-hdkey": {
          "is-private": false,
          "key-data": "021a3bf5fbf737d0f36993fd46dc4913093beb532d654fe0dfd98bd27585dc9f29",
          "use-info": {
            "crypto-coin-info": {}
          },
          "origin": {
            "crypto-keypath": {
              "components": [
                48,
                true,
                0,
                true,
                0,
                true,
                2,
                true
              ],
              "source-fingerprint": 1942346250,
              "depth": 4
            }
          },
          "chain-code": "bba0c7ca160a870efeb940ab90d0f4284fea1b5e0d2117677e823fc37e2d5763",
          "parent-fingerprint": 485660438,
          "name": "BitTool Signer",
          "note": "BitTool Signer public account"
        }
      }
    }
  ]
}
QR text
UR:CRYPTO-ACCOUNT/OEADCYJKSKTNBKAOLYTAADMETAADDLPDAOWKAXHDCLAOCYFRYKZOYLEMTIWFINMUZCFGUOGABWASFRWMGUDPIHGWVTURTALUTDKPLPUONEDTAHTAADEHNBAMTAADDYOTADLOCSDYYKAEYKAEYKAOYKAOCYJKSKTNBKAXAAAAHDCXRKNBSTSGCMBKLTBAZERHFZPYMHTIWKDEGWWDCWHYBTCLCHIOKBLFFHSRKBDPHGIAAYCYCEWZMSCMASJTFWINJYGHJLJLJZCXGUINIOJTIHJPBKKSCAFWINJYGHJLJLJZCXGUINIOJTIHJPCXJOKPIDJZINIACXHSIAIAJLKPJTJYVEGWJLEO

EVM: crypto-hdkey​

The EVM export is the account node m/44'/60'/0' as a top-level crypto-hdkey (EIP-4527), the format MetaMask, Rabby, imToken and others import:

KeyFieldValue
2is-privatefalse
3key-data33-byte compressed public key
4chain-code32 bytes
5use-info305({1: 60})
6origin304({1: [44, true, 60, true, 0, true], 2: fingerprint, 3: 3})
7children304({1: [0, false, [], false]}), i.e. 0/*
8parent-fingerprintuint32
9, 10name, note"BitTool Signer", "BitTool Signer public account"

Derive …/0/i for addresses. The same key serves every supported EVM network.

m/44'/60'/0' · crypto-hdkeyFirst address: 0x9858EfFD232B4033E47d90003D41EC34EcaEda94
UR:CRYPTO-HDKEY/PTAOWKAXHDCLAOWDVEROKOPDINHSEEROISYALKSAYKCTJSHEDPRNUYJYFGROVAWEWFTYGHCEGLRPKGAHTAADEHOYADCSFNAMTAADDYOTADLNCSDWYKCSFNYKAEYKAOCYJKSKTNBKAXAXAAHDCXTPLFJSLUKNFWLAISAXWYPALBJYLSWZAMCXHSCYUYLOZTMWFNLDLGSKPYPTGSDECFAYCYTEDMFEAYATTAADDYOYADLRAEWKLAWKASJTFWINJYGHJLJLJZCXGUINIOJTIHJPBKKSCAFWINJYGHJLJLJZCXGUINIOJTIHJPCXJOKPIDJZINIACXHSIAIAJLKPJTJYMUFLSAVD
Decoded payload
{
  "is-private": false,
  "key-data": "02eae4b876a8696134b868f88cc2f51f715f2dbedb7446b8e6edf3d4541c4eb67b",
  "use-info": {
    "crypto-coin-info": {
      "type": 60
    }
  },
  "origin": {
    "crypto-keypath": {
      "components": [
        44,
        true,
        60,
        true,
        0,
        true
      ],
      "source-fingerprint": 1942346250,
      "depth": 3
    }
  },
  "chain-code": "d882718b7a42806803eeb17f7483f20620611adb88fc943c898dc5aba94c2819",
  "parent-fingerprint": 3543024904,
  "children": {
    "crypto-keypath": {
      "components": [
        0,
        false,
        [],
        false
      ]
    }
  },
  "name": "BitTool Signer",
  "note": "BitTool Signer public account"
}
QR text
UR:CRYPTO-HDKEY/PTAOWKAXHDCLAOWDVEROKOPDINHSEEROISYALKSAYKCTJSHEDPRNUYJYFGROVAWEWFTYGHCEGLRPKGAHTAADEHOYADCSFNAMTAADDYOTADLNCSDWYKCSFNYKAEYKAOCYJKSKTNBKAXAXAAHDCXTPLFJSLUKNFWLAISAXWYPALBJYLSWZAMCXHSCYUYLOZTMWFNLDLGSKPYPTGSDECFAYCYTEDMFEAYATTAADDYOYADLRAEWKLAWKASJTFWINJYGHJLJLJZCXGUINIOJTIHJPBKKSCAFWINJYGHJLJLJZCXGUINIOJTIHJPCXJOKPIDJZINIACXHSIAIAJLKPJTJYMUFLSAVD

Solana: crypto-multi-accounts​

Solana keys are fully hardened, so there is nothing to derive from. The export holds one preset key (the one selected in the app) as a crypto-hdkey with a 32-byte Ed25519 key:

crypto-multi-accounts = {
  1: master-fingerprint,
  2: [ 303({ 2: false, 3: <32-byte public key>, 5: 305({1: 501}), 6: 304(<path>), 9: name, 10: note }) ],
  3: "BitTool Signer",          ; device
  5: "1.0.0"                    ; version
}
PresetPath
Standardm/44'/501'/0'/0'
Trustm/44'/501'/0'
Legacym/44'/501'

The address is the Base58 encoding of the 32-byte key.

Decoded payload (standard preset)
{
  "master-fingerprint": 1942346250,
  "keys": [
    {
      "crypto-hdkey": {
        "is-private": false,
        "key-data": "f036276246a75b9de3349ed42b15e232f6518fc20f5fcd4f1d64e81f9bd258f7",
        "use-info": {
          "crypto-coin-info": {
            "type": 501
          }
        },
        "origin": {
          "crypto-keypath": {
            "components": [
              44,
              true,
              501,
              true,
              0,
              true,
              0,
              true
            ],
            "source-fingerprint": 1942346250,
            "depth": 4
          }
        },
        "name": "BitTool Signer",
        "note": "BitTool Signer public account"
      }
    }
  ],
  "device": "BitTool Signer",
  "version": "1.0.0"
}
QR text
UR:CRYPTO-MULTI-ACCOUNTS/OXADCYJKSKTNBKAOLYTAADDLOLAOWKAXHDCXWTENDIIDFGOSHPNTVLEENNTYDNBZVOEYYNGYMYSABSHESNGWCAIEVSCTNDTDHDYLAHTAADEHOYADCFADYKAMTAADDYOTADLOCSDWYKCFADYKYKAEYKAEYKAOCYJKSKTNBKAXAAASJTFWINJYGHJLJLJZCXGUINIOJTIHJPBKKSCAFWINJYGHJLJLJZCXGUINIOJTIHJPCXJOKPIDJZINIACXHSIAIAJLKPJTJYAXJTFWINJYGHJLJLJZCXGUINIOJTIHJPAHIHEHDMDYDMDYMSFNHFVA

Plain addresses​

The Address option exports just the address as QR text: no URI scheme, no amount, no UR wrapper. It is for watch-only wallets that cannot import keys. TRON is always exported this way, at any index the user picks (m/44'/195'/0'/0/i, 0 ≤ i < 231).

ExportQR text
Bitcoin (Native SegWit, index 0)bc1qcr8te4kr609gcawutmrza0j4xv80jy8z306fyu
EVM (index 0)0x9858EfFD232B4033E47d90003D41EC34EcaEda94
Solana (standard)HAgk14JpMQLgt6rVgv7cBQFJWFto5Dqxi472uT3DKpqk
TRON index 0TUEZSdKsoDHQMeZwihtdoBiN46zxhGWYdH
TRON index 5TBdYXtwq18cAhi1BA574TrP6tw2G86anu1

A wallet that pairs by address alone cannot add derivation data to its signing requests. BitTool Signer can still match address-only requests for EVM index 0 and TRON indexes 0–99, but prefer the key exports when you plan to sign.

Decoding all of them​

One function for every coin-level export, using cborg with the descriptor tags preserved:

examples/coin-level.mjs
import { URDecoder } from '@ngraveio/bc-ur';
import { decode, Tagged } from 'cborg';
import { HDKey } from '@scure/bip32';
import { base58 } from '@scure/base';

// Output-descriptor tags (BCR-2020-010) → script names.
const SCRIPT = { 400: 'sh', 401: 'wsh', 403: 'pkh', 404: 'wpkh', 409: 'tr' };
const options = { useMaps: true, strict: true, tags: Tagged.preserve(303, 304, 305, 400, 401, 403, 404, 409) };

const fingerprint = (n) => n.toString(16).padStart(8, '0');
const pathOf = (keypath) => {                        // Tagged(304, Map{1: [index, hardened, …]})
  const c = keypath.value.get(1), parts = [];
  for (let i = 0; i < c.length; i += 2) parts.push(`${c[i]}${c[i + 1] ? "'" : ''}`);
  return `m/${parts.join('/')}`;
};
const accountOf = (hdkey) => {                       // crypto-hdkey map: 3 key, 4 chain code, 6 origin, 8 parent fp
  const origin = hdkey.get(6).value.get(1);
  return {
    path: pathOf(hdkey.get(6)),
    masterFingerprint: fingerprint(hdkey.get(6).value.get(2)),
    xpub: new HDKey({ publicKey: hdkey.get(3), chainCode: hdkey.get(4), depth: origin.length / 2,
      index: origin.at(-2) + (origin.at(-1) ? 0x80000000 : 0), parentFingerprint: hdkey.get(8) }).publicExtendedKey,
  };
};

/** Reads any coin-level export from BitTool Signer. */
export function readCoinLevelQR(frames) {
  if (frames.length === 1 && !/^ur:/i.test(frames[0])) return { kind: 'address', address: frames[0].trim() };
  const decoder = new URDecoder();
  for (const frame of frames) decoder.receivePart(frame);
  if (!decoder.isSuccess()) throw new Error('Incomplete or invalid QR');
  const ur = decoder.resultUR();
  const cbor = decode(ur.cbor, options);

  switch (ur.type) {
    case 'crypto-account': {                         // Bitcoin: {1: master fp, 2: [output descriptor]}
      let node = cbor.get(2)[0];
      const script = [];
      while (node.tag !== 303) { script.push(SCRIPT[node.tag]); node = node.value; }   // e.g. sh → wpkh
      return { kind: 'bitcoin', script: script.join('-'), ...accountOf(node.value) };
    }
    case 'crypto-hdkey':                             // EVM account node
      return { kind: 'evm', ...accountOf(cbor) };
    case 'crypto-multi-accounts': {                  // Solana: {1: master fp, 2: [crypto-hdkey with a 32-byte key]}
      const key = cbor.get(2)[0].value;
      return { kind: 'solana', masterFingerprint: fingerprint(cbor.get(1)), path: pathOf(key.get(6)), address: base58.encode(key.get(3)) };
    }
    default:
      throw new Error(`Not a pairing QR: ${ur.type}`);
  }
}