@shakesco/silent

Shakesco does not offer silent payments. These pages document an open source library you can add to your own app or website. The Shakesco app does not send or receive silent payments.

Built by the community - Special thanks to Ruben Somsen and Josie Bake for their groundbreaking work on BIP-352.

Installation

npm i @shakesco/silent

Import the SDK:

const shakesco = require("@shakesco/silent");
const {
  KeyGeneration,
  SilentPaymentDestination,
  SilentPaymentBuilder,
  ECPrivateInfo,
  Network,
  BitcoinScriptOutput,
  bip32,
  bip39,
} = shakesco;

Integration Workflow

Generate silent payment address

Create a reusable address for receiving private payments

Create destination address

Generate a one-time taproot address for each payment

Scan for incoming funds

Detect payments without exposing spending keys

Spend received funds

Derive private keys and move Bitcoin

Step 1: Generate Silent Payment Address

Choose your key generation method based on your use case:

From Private Keys (Recommended)
From Mnemonic (Wallets)

Best for: Non-wallet applications where users control their keys

const b_scan = ""; // Scan private key
const b_spend = ""; // Spend private key

const keys = KeyGeneration.fromPrivateKeys({
  b_scan: b_scan,
  b_spend: b_spend,
  network: "testnet",
});

const silentPaymentAddress = keys.toAddress();
console.log(silentPaymentAddress);

Pro tip: Make users sign a message, then derive b_scan and b_spend from the ECDSA signature:

Use r as b_scan
Use s as b_spend (or vice versa)

This ensures cryptographically secure randomness without storing additional keys.

Best for: Wallet providers managing user funds

const mnemonic = ""; // 12, 15, or 24 word phrase
const keys = KeyGeneration.fromMnemonic(mnemonic);
const silentPaymentAddress = keys.toAddress();
console.log(silentPaymentAddress);

Alternative: From HD key directly

const seed = bip39.mnemonicToSeedSync(mnemonic);
const node = bip32.fromSeed(seed);
const keys = KeyGeneration.fromHd(node);
const silentPaymentAddress = keys.toAddress();

If not using the signature-derived method, ensure you’re using a cryptographically secure random number generator for b_scan and b_spend.

Create a Change Address

Critical for privacy: Never send change to a public address after making silent payments.

const keys = KeyGeneration.fromPrivateKeys({
  b_scan: b_scan,
  b_spend: b_spend,
  network: "testnet",
});

// Always use label 0 for change (per BIP-352 spec)
const changeSilentPaymentAddress = keys.toLabeledSilentPaymentAddress(0);
console.log(changeSilentPaymentAddress.toAddress());

Why this matters

Scenario: You send 10 silent payments to friends, then send change to your public address.Result: You’ve exposed:

❌ Your own private transaction history
❌ Your friends’ payment patterns
❌ Links between all 10 transactions

Solution: Always use a labeled silent payment address for change.Reference: BIP-352 Labels for Change

Step 2: Create Destination Address

Generate a unique taproot address for the payment:

// Parse recipient's silent payment address
const addressPubKeys = KeyGeneration.fromAddress(silentPaymentAddress);

// Your UTXO details
const vinOutpoints = [
  {
    txid: "367e24cac43a7d77621ceb1cbc1cf4a7719fc81b05b07b38f99b043f4e8b95dc",
    index: 1,
  },
];

const pubkeys = [
  "025c471f0e7d30d6f9095058bbaedaf13e1de67dbfcbe8328e6378d2a3bfb5cfd0",
];

const UTXOPrivatekey = ""; // Your UTXO private key

// Build the destination
const builder = new SilentPaymentBuilder({
  vinOutpoints: vinOutpoints,
  pubkeys: pubkeys,
}).createOutputs(
  [
    new ECPrivateInfo(
      UTXOPrivatekey,
      false // Set true if output is from taproot
    ),
  ],
  [
    new SilentPaymentDestination({
      amount: 1000, // Satoshis (1 BTC = 100,000,000 sats)
      network: Network.Testnet,
      version: 0,
      scanPubkey: addressPubKeys.B_scan,
      spendPubkey: addressPubKeys.B_spend,
    }),
  ]
);

// Get the destination taproot address
const destinationAddress = builder[silentPaymentAddress][0];
console.log("Send 1000 sats to:", destinationAddress);

What you need:

UTXO transaction ID and output index
UTXO private key
Amount in satoshis
Recipient’s scan and spend public keys (B_scan, B_spend)

Step 3: Scan for Incoming Funds

Scanning trade-off: This is the main drawback of silent payments - you must scan the blockchain to detect incoming transactions.

Check if a transaction belongs to you:

const vinOutpoints = [
  {
    txid: "367e24cac43a7d77621ceb1cbc1cf4a7719fc81b05b07b38f99b043f4e8b95dc",
    index: 1,
  },
];

const pubkeys = [
  "025c471f0e7d30d6f9095058bbaedaf13e1de67dbfcbe8328e6378d2a3bfb5cfd0",
];

const search = new SilentPaymentBuilder({
  vinOutpoints: vinOutpoints,
  pubkeys: pubkeys,
  network: Network.Testnet,
}).scanOutputs(
  keys.b_scan, // Your scan private key
  keys.B_spend, // Your spend public key
  [
    new BitcoinScriptOutput(
      "5120fdcb28bcea339a5d36d0c00a3e110b837bf1151be9e7ac9a8544e18b2f63307d",
      BigInt(1000)
    ),
  ]
);

const foundOutput =
  search[builder[keys.toAddress()][0].address.pubkey.toString("hex")].output;
console.log(foundOutput);

If the output matches the taproot address → it’s yours! 🎉

What you need for scanning

Transaction input’s txid and output_index
Public key from the output
Script and amount from the taproot address

Learn more: BIP-352 Scanning

Step 4: Spend the Funds

Once you’ve confirmed funds belong to you, derive the private key:

const vinOutpoints = [
  {
    txid: "367e24cac43a7d77621ceb1cbc1cf4a7719fc81b05b07b38f99b043f4e8b95dc",
    index: 1,
  },
];

const pubkeys = [
  "025c471f0e7d30d6f9095058bbaedaf13e1de67dbfcbe8328e6378d2a3bfb5cfd0",
];

const private_key = new SilentPaymentBuilder({
  vinOutpoints: vinOutpoints,
  pubkeys: pubkeys,
}).spendOutputs(keys.b_scan, keys.b_spend);

console.log("Private key:", private_key);

Use this private key with bitcoinjs-lib to build and sign your taproot transaction.

That’s It

You’ve successfully implemented Bitcoin silent payments. Your users can now:

✅ Share a single address for all payments
✅ Receive Bitcoin privately
✅ Maintain transaction unlinkability
✅ Avoid notification transaction fees

Additional Resources

BIP-352 Specification

Complete technical specification

bitcoinjs-lib

Build Bitcoin transactions in JavaScript

Silent Payments Explained

Protocol deep dive

ECDSA Signatures

Learn about signature-based key derivation

Getting started

Loyalty Program

Payment Links

Auto-Payments (Beta)

Pay Team (Beta)

Silent Payments

Smart Contracts

Installation

Integration Workflow

Step 1: Generate Silent Payment Address

Create a Change Address

Step 2: Create Destination Address

Step 3: Scan for Incoming Funds

Step 4: Spend the Funds

That’s It

Additional Resources

BIP-352 Specification

bitcoinjs-lib

Silent Payments Explained

ECDSA Signatures

​Installation

​Integration Workflow

​Step 1: Generate Silent Payment Address

​Create a Change Address

​Step 2: Create Destination Address

​Step 3: Scan for Incoming Funds

​Step 4: Spend the Funds

​That’s It

​Additional Resources

BIP-352 Specification

bitcoinjs-lib

Silent Payments Explained

ECDSA Signatures

Installation

Integration Workflow

Step 1: Generate Silent Payment Address

Create a Change Address

Step 2: Create Destination Address

Step 3: Scan for Incoming Funds

Step 4: Spend the Funds

That’s It

Additional Resources