example: watch only wallet

docs/Examples/watch-only-wallet.js

@@ -0,0 +1,62 @@
+const {HDPrivateKey,Network} = require('bcoin');
+const {Mnemonic} = require('bcoin/lib/hd');
+const {WalletClient} = require('bclient');
+
+(async () => {
+
+  // use well know test passphrase
+  const phrase = [
+    'abandon',
+    'abandon',
+    'abandon',
+    'abandon',
+    'abandon',
+    'abandon',
+    'abandon',
+    'abandon',
+    'abandon',
+    'abandon',
+    'abandon',
+    'about',
+  ].join(' ');
+
+  const network = Network.get('main');
+
+  const mnemonic = Mnemonic.fromPhrase(phrase);
+
+  // m'
+  const priv = HDPrivateKey.fromMnemonic(mnemonic);
+
+  // m'/44'
+  const bip44Key = priv.derive(44, true);
+
+  // m'/44'/0'
+  const bitcoinKey = bip44Key.derive(0, true);
+
+  // m'/44'/0'/0'
+  const accountKey = bitcoinKey.derive(0, true);
+
+  // account extended public key
+  // https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#Serialization_format
+  const xpub = accountKey.xpubkey(network.type);
+
+  // recommended to use hardware wallet to derive keys
+  // see github.com/bcoin-org/bledger
+
+  const client = new WalletClient({
+    network: network.type,
+    port: network.walletPort,
+  });
+
+  // create watch only wallet
+  // the wallet will generate lookahead
+  // addresses from the account extended public key
+  // and can find spendable coins in the blockchain state
+  const response = await client.createWallet('mywallet', {
+    accountKey: xpub,
+    watchOnly: true,
+  });
+
+})();
+
+

docs/README.md

@@ -25,6 +25,7 @@ Welcome to the bcoin docs!
 - [Miner with WorkerPool][example-miner-configs]
 - [Create and Sign TX][example-tx-create-sign]
 - [Get Transaction from Chain][example-tx-from-chain]
+- [Create Watch Only Wallet][example-watch-only-wallet]
 
 
 [getting-started]: Beginner's-Guide.md
@@ -49,3 +50,4 @@ Welcome to the bcoin docs!
 [example-simple-fullnode]: Examples/fullnode.js
 [example-tx-create-sign]: Examples/create-sign-tx.js
 [example-tx-from-chain]: Examples/get-tx-from-chain.js
+[example-watch-only-wallet]: Examples/watch-only-wallet.js