Privacy Boost SDK

Privacy Boost is a privacy-preserving transaction SDK that enables confidential token transfers on EVM-compatible blockchains. Build private payment flows across web, mobile, and CLI with a unified API.

How It Works

Privacy Boost uses a shielded pool — a smart contract that holds deposited tokens using encrypted commitments — combined with zero-knowledge proofs to enable private transactions in three steps:

Deposit — Move tokens from your wallet into the shielded pool
Send — Transfer tokens privately to any privacy address (fully hidden from observers)
Withdraw — Move tokens back to any public address

Once tokens are in the shielded pool, transfers are completely private: no one can see the sender, recipient, or amount. Learn more about the privacy model.

Core Concepts

Before diving in, here are the key terms you’ll encounter throughout the SDK:

Concept	What it means
Shielded pool	The on-chain smart contract that holds deposited tokens. Once tokens are in the pool, all transfers are private.
Shielded balance	Your private token balance inside the shielded pool — only visible to you.
Privacy address	A public address others use to send you private transfers. Derived from your wallet, similar to sharing a bank account number. Not the same as your Ethereum address.
Vault	The SDK module (`sdk.vault`) for all shielded pool operations — deposit, send, unshield, and balance queries.
Wallet adapter	A platform-specific object that bridges the SDK and your wallet. It provides signing functions (`signMessage`, `signTypedData`, `sendTransaction`). Each platform implements this interface differently.
Chain client	A chain-scoped client created via `sdk.forChain()` for multi-chain operations. Each chain client has its own auth state and balances but shares identity keys with the parent SDK.

For protocol-level details (UTXO model, notes, nullifiers, Merkle trees), see the Protocol Deep Dive. For key hierarchy and encryption, see Keys & Encryption. For a full glossary, see Glossary.

Quick Example

import { PrivacyBoost } from '@sunnyside-io/privacy-boost';
import { createWalletAdapter } from '@sunnyside-io/privacy-boost-react';

// Initialize
const sdk = await PrivacyBoost.create({
  serverUrl: 'https://optimism.sepolia.privacyboost.io',
  wethContractAddress: '0x4200000000000000000000000000000000000006',
  appId: 'app_abc123xyz',
});

// Authenticate with browser wallet (MetaMask, etc.)
const adapter = createWalletAdapter();
await sdk.auth.authenticate(adapter);

// Deposit 1 token into the shielded pool
await sdk.vault.shield({
  tokenAddress: '0x...token-address',
  amount: 1000000000000000000n, // 1 token (18 decimals)
});

// Send 0.5 tokens privately
await sdk.vault.send({
  to: '0x04...recipient-privacy-address',
  tokenAddress: '0x...token-address',
  amount: 500000000000000000n, // 0.5 tokens
});

import { PrivacyBoostProvider, useAuth, useVault } from '@sunnyside-io/privacy-boost-react';

function App() {
  return (
    <PrivacyBoostProvider config={{
      serverUrl: 'https://optimism.sepolia.privacyboost.io',
      wethContractAddress: '0x4200000000000000000000000000000000000006',
      appId: 'app_abc123xyz',
    }}>
      <WalletUI />
    </PrivacyBoostProvider>
  );
}

function WalletUI() {
  const { authenticateWithWalletAdapter, isAuthenticated, privacyAddress } = useAuth();
  const { shield } = useVault();

  if (!isAuthenticated) {
    return <button onClick={authenticateWithWalletAdapter}>Connect Wallet</button>;
  }

  return (
    <div>
      <p>Privacy Address: {privacyAddress}</p>
      <button onClick={() => shield({ tokenAddress: '0x...', amount: '1.0' })}>
        Deposit 1 Token
      </button>
    </div>
  );
}

Getting Started Path

Try a Quickstart

Pick your platform below and follow the 5-minute quickstart to get a working integration.

Set up your app

Read App Setup to get an App ID, then Configuration and Authentication to understand the setup options.

Go deeper with your platform SDK

Each platform has a full Getting Started guide and topic-specific guides (vault operations, session management, error handling).

Prepare for production

Choose an auth integration for your backend, configure key persistence, and add error handling.

Choose Your Platform

TypeScript

Full-featured SDK for web applications. Works in browser and Node.js.

React

React hooks and components for seamless integration with your React app.

iOS

Native Swift SDK with async/await support for iOS applications.

Android

Native Kotlin SDK with coroutines for Android applications.

React Native

React Native SDK with native wallet integration.

CLI

Command-line tool for scripting, automation, and testing.

Multi-Chain Support

Privacy Boost supports operating across multiple EVM-compatible blockchains from a single SDK instance. Create chain-scoped clients to deposit, transfer, and withdraw on any supported chain while sharing your cryptographic identity.

const ethereum = sdk.forChain({ serverUrl: 'https://eth.example.com' });
await ethereum.authenticate(walletAdapter);
await ethereum.vault.shield({ tokenAddress: '0x...', amount: 1000n });

See the Multi-Chain guide for details.

Learn More

Multi-Chain

Operate across multiple blockchains with a single SDK instance

Protocol Deep Dive

UTXO model, notes, nullifiers, Merkle trees, and full transaction lifecycle

Keys & Encryption

Key hierarchy, privacy addresses, and 3-way ECDH encryption

Trust & Security

TEE guarantees, self-custody, forced withdrawal, and threat model

Glossary

Technical terminology and definitions

​Privacy Boost SDK

​How It Works

​Core Concepts

​Quick Example

​Getting Started Path

​Choose Your Platform