Building an App with the SDK

This guide walks you through building a complete confidential decentralized application using the Stabletrust SDK and Privy for wallet authentication. By the end, you will have a working Next.js application where users can deposit tokens into an encrypted balance, transfer them privately onchain, and withdraw back to a public balance.

Stabletrust SDK Demo

The complete source code for this guide.

What You Are Building

Stabletrust uses Homomorphic Encryption (HE) to give each user a confidential token balance alongside their normal public balance. Once tokens enter the confidential layer, their amounts are encrypted onchain opaque to block explorers and other observers. The user flow:

Connect wallet via Privy.
Initialize a confidential account, which generates the user’s HE keypair through a wallet signature.
Deposit public tokens into the encrypted layer, transfer privately to another address, and withdraw back to a public balance when needed.

Stack used in this guide:

Next.js 16 (App Router, TypeScript)
Privy for embedded wallet and authentication
ethers.js v6 for signer management and amount formatting
@fairblock/stabletrust for confidential operations
viem for chain definitions

Prerequisites

Node.js 18 or higher
A Privy App ID created at dashboard.privy.io
A wallet funded with test ETH on Base Sepolia for gas

Step 1: Create the Next.js Application

npx create-next-app@latest example
cd example

When prompted, choose: TypeScript, ESLint, Tailwind CSS, App Router.

Step 2: Install Dependencies

npm install @privy-io/react-auth viem ethers @fairblock/stabletrust

Package	Role
`@privy-io/react-auth`	Wallet connection and authentication
`viem`	Chain definitions for Privy configuration
`ethers`	Signer extraction, amount parsing and formatting
`@fairblock/stabletrust`	Confidential deposit, transfer, withdraw

Step 3: Environment Variables

Create .env.local in the root of your project:

NEXT_PUBLIC_PRIVY_APP_ID=your_privy_app_id_here
NEXT_PUBLIC_RPC_URL=https://base-sepolia.drpc.org
NEXT_PUBLIC_TOKEN_ADDRESS=0x036CbD53842c5426634e7929541eC2318f3dCF7e
NEXT_PUBLIC_CHAIN_ID=84532

NEXT_PUBLIC_PRIVY_APP_ID: from your Privy dashboard
NEXT_PUBLIC_RPC_URL: the JSON-RPC endpoint for Base Sepolia
NEXT_PUBLIC_TOKEN_ADDRESS: the ERC20 token for this demo (test USDC on Base Sepolia)
NEXT_PUBLIC_CHAIN_ID: 84532 is Base Sepolia

Step 4: Add the Privy Provider

Privy must wrap the entire application so its authentication context is available everywhere. Create app/Providers.tsx:

'use client';

import { PrivyProvider } from '@privy-io/react-auth';
import { baseSepolia } from 'viem/chains';

export const supportedChains = [baseSepolia];

export default function Providers({ children }: { children: React.ReactNode }) {
  return (
    <PrivyProvider
      appId={process.env.NEXT_PUBLIC_PRIVY_APP_ID!}
      config={{
        appearance: {
          theme: 'light',
          accentColor: '#000000',
        },
        supportedChains: supportedChains,
        defaultChain: baseSepolia,
      }}
    >
      {children}
    </PrivyProvider>
  );
}

supportedChains and defaultChain lock the app to Base Sepolia so the wallet always targets the correct network. You can see the complete Provider implementation here: app/Providers.tsx Then wrap your layout in app/layout.tsx:

import Providers from './Providers';

export default function RootLayout({
  children,
}: {
  children: React.ReactNode;
}) {
  return (
    <html lang="en">
      <body>
        <Providers>{children}</Providers>
      </body>
    </html>
  );
}

All components inside now have access to usePrivy() and useWallets(). You can see the complete Providers.tsx used in the demo here: app/Providers.tsx

Step 5: Building the Hook, Step by Step

Everything from this point forward lives inside a single React hook: app/hooks/useConfidentialClient.ts. This section builds it piece by piece so each operation is clear before the next one is added. Start by creating the file with its imports and state:

// app/hooks/useConfidentialClient.ts
'use client';

import { useState, useEffect } from 'react';
import { usePrivy, useWallets } from '@privy-io/react-auth';
import { ethers } from 'ethers';
import { ConfidentialTransferClient } from '@fairblock/stabletrust';

const config = {
  rpcUrl: process.env.NEXT_PUBLIC_RPC_URL!,
  chainId: Number(process.env.NEXT_PUBLIC_CHAIN_ID!),
  tokenAddress: process.env.NEXT_PUBLIC_TOKEN_ADDRESS!,
};

export function useConfidentialClient() {
  const { authenticated } = usePrivy();
  const { wallets } = useWallets();

  const [client, setClient] = useState<ConfidentialTransferClient | null>(null);
  const [signer, setSigner] = useState<ethers.Signer | null>(null);
  const [userKeys, setUserKeys] = useState<{
    publicKey: string;
    privateKey: string;
  } | null>(null);
  const [balances, setBalances] = useState({
    public: '0',
    confidential: '0',
    native: '0',
  });
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [tokenDecimals, setTokenDecimals] = useState(6);
  const [tokenSymbol, setTokenSymbol] = useState('TOKEN');

  // ... operations are added below
}

Each of the following sections adds one piece to this hook.

5.1 Initialize the SDK Client

The ConfidentialTransferClient is the entry point to all SDK operations. It connects to the network and resolves the correct Stabletrust contract automatically from the chain ID. Add this useEffect to your hook:

useEffect(() => {
  const c = new ConfidentialTransferClient(
    config.rpcUrl, // rpcUrl: JSON-RPC endpoint for the target network
    config.chainId // chainId: used to auto-resolve the Stabletrust contract address
  );
  setClient(c);
}, []);

Parameters for new ConfidentialTransferClient:

Parameter	Type	Description
`rpcUrl`	`string`	The HTTP JSON-RPC endpoint of the network
`chainId`	`number`	The chain ID. The SDK resolves the Stabletrust contract address from this.

You only need one client instance for the lifetime of the app. Creating it once on mount is sufficient. Custom deployments. If you are pointing at a custom Stabletrust deployment rather than one the SDK resolves automatically from the chain ID, pass the contract address explicitly as a middle argument:

const c = new ConfidentialTransferClient(
  config.rpcUrl,
  '0xYourCustomStabletrustContract', // explicit contract address
  config.chainId
);

5.2 Wrap the Privy Wallet into an Ethers Signer

The Stabletrust SDK expects a standard ethers.Signer. Privy provides its own wallet abstraction, so you need to extract the raw EIP-1193 provider from it and wrap it with ethers. Add this useEffect to your hook it runs whenever authentication state or the wallet list changes:

useEffect(() => {
  async function setupSigner() {
    if (authenticated && wallets.length > 0) {
      const wallet = wallets[0];

      // 1. Switch to the correct chain before doing anything
      await wallet.switchChain(config.chainId);

      // 2. Get the raw EIP-1193 provider from Privy
      const provider = await wallet.getEthereumProvider();

      // 3. Wrap it in ethers.BrowserProvider
      const ethersProvider = new ethers.BrowserProvider(provider);

      // 4. Derive the Signer this is what the SDK expects
      const s = await ethersProvider.getSigner();
      setSigner(s);
    } else {
      setSigner(null);
    }
  }
  setupSigner();
}, [authenticated, wallets]);

What each step does:

switchChain: forces the wallet onto the correct network before any transaction is signed. Without this, the user could accidentally sign on the wrong chain.
getEthereumProvider(): returns the raw EIP-1193 provider Privy uses internally.
BrowserProvider: the ethers.js v6 wrapper for browser-injected providers.
getSigner(): returns a JsonRpcSigner capable of signing transactions and messages.

The signer produced here is passed into every SDK operation below.

5.3 Initialize the Confidential Account

Before any confidential operation can happen, the user must have a confidential account registered onchain with their HE public key. ensureAccount handles the full flow in one call: it prompts a wallet signature, derives the HE keypair from that signature, and registers the public key onchain if it does not yet exist. Add this function to your hook:

const ensureAccount = async () => {
  if (!client || !signer) throw new Error('Not initialized');
  setLoading(true);
  setError(null);
  try {
    const keys = await client.ensureAccount(
      signer // ethers.Signer the user's signer derived from the Privy wallet
    );
    setUserKeys(keys);
  } catch (e: any) {
    setError(e.message);
  } finally {
    setLoading(false);
  }
};

Parameters for client.ensureAccount:

Parameter	Type	Description
`signer`	`ethers.Signer`	The user’s signer derived from the Privy wallet

Returns: { publicKey: string, privateKey: string } The privateKey returned here is a derived HE key, not the user’s wallet private key. It never leaves the browser and is re-derived on each session from the wallet signature. Store it in React state and pass it to getConfidentialBalance later.

Account initialization includes an onchain finalization step. Expect this to take approximately 45 seconds on the first call. The method waits for finalization before returning, so loading will be true for the duration.

5.4 Deposit: Move Tokens into the Confidential Layer

Deposit converts public ERC20 tokens into an encrypted confidential balance. The SDK handles the ERC20 approval and the deposit transaction in a single call you do not need to send a separate approve transaction. Add this function to your hook:

const confidentialDeposit = async (humanAmount: string) => {
  if (!client || !signer) throw new Error('Not initialized');
  setLoading(true);
  setError(null);
  try {
    // Convert the human-readable amount to token base units
    const amount = ethers.parseUnits(humanAmount, tokenDecimals);
    // e.g. "10" with 6 decimals → 10_000_000n

    await client.confidentialDeposit(
      signer, // ethers.Signer the user's wallet signer
      config.tokenAddress, // string the ERC20 contract address to deposit
      amount // BigInt amount in token base units
    );

    // Wait briefly for the chain state to settle, then refresh balances
    setTimeout(() => fetchBalances(), 2000);
  } catch (e: any) {
    setError(e.message);
  } finally {
    setLoading(false);
  }
};

Parameters for client.confidentialDeposit:

Parameter	Type	Description
`signer`	`ethers.Signer`	The user’s wallet signer
`tokenAddress`	`string`	The ERC20 token contract address
`amount`	`BigInt`	Amount in the token’s base unit always use `ethers.parseUnits` to convert

Returns: A transaction receipt once the deposit is confirmed and finalized onchain.

Always use ethers.parseUnits(humanAmount, decimals) to convert. Never pass a raw decimal number directly - the SDK expects base units as a BigInt.

5.5 Withdraw: Move Tokens Back to Public

Withdraw removes tokens from the encrypted confidential balance and returns them to the user’s standard ERC20 balance. After withdrawal, the amount is visible onchain again. Add this function to your hook:

const withdraw = async (humanAmount: string) => {
  if (!client || !signer) throw new Error('Not initialized');
  setLoading(true);
  setError(null);
  try {
    // Convert to base units, then cast to Number as the withdraw method expects
    const amount = ethers.parseUnits(humanAmount, tokenDecimals);

    await client.withdraw(
      signer, // ethers.Signer the user's wallet signer
      config.tokenAddress, // string the ERC20 token contract address
      Number(amount) // number amount in base units, cast to Number
    );

    setTimeout(() => fetchBalances(), 2000);
  } catch (e: any) {
    setError(e.message);
  } finally {
    setLoading(false);
  }
};

Parameters for client.withdraw:

Parameter	Type	Description
`signer`	`ethers.Signer`	The user’s wallet signer
`tokenAddress`	`string`	The ERC20 token contract address
`amount`	`number`	Amount in token base units pass as `Number(ethers.parseUnits(...))`

Returns: A transaction receipt.

Unlike confidentialDeposit, withdraw takes a number, not a BigInt. Always cast with Number(ethers.parseUnits(...)).

5.6 Transfer Send Tokens Privately

Confidential transfer sends tokens from the caller’s encrypted balance to another address’s encrypted balance. The amount is encrypted onchain: block explorers show that a transfer occurred and between which addresses, but not the value moved. The sender and recipient addresses stay visible this client hides amounts, not identities. If you also need to hide the sender’s address, use the Unlinkable Transfers flow. Add this function to your hook:

const confidentialTransfer = async (
  recipientAddress: string,
  humanAmount: string
) => {
  if (!client || !signer) throw new Error('Not initialized');
  setLoading(true);
  setError(null);
  try {
    const amount = ethers.parseUnits(humanAmount, tokenDecimals);

    await client.confidentialTransfer(
      signer, // ethers.Signer the sender's wallet signer
      recipientAddress, // string the recipient's public Ethereum address (0x...)
      config.tokenAddress, // string the ERC20 token contract address
      Number(amount) // number amount in base units, cast to Number
    );

    setTimeout(() => fetchBalances(), 2000);
  } catch (e: any) {
    setError(e.message);
  } finally {
    setLoading(false);
  }
};

Parameters for client.confidentialTransfer:

Parameter	Type	Description
`signer`	`ethers.Signer`	The sender’s wallet signer
`recipientAddress`	`string`	The recipient’s public Ethereum address (`0x...`)
`tokenAddress`	`string`	The ERC20 token contract address
`amount`	`number`	Amount in token base units pass as `Number(ethers.parseUnits(...))`

Returns: A transaction receipt.

The recipient must have already called ensureAccount and have a registered confidential account before you can transfer to them. If their account does not exist onchain, the transaction fails with "Account does not exist".

5.7 Fetch the Confidential Balance

The confidential balance is stored encrypted onchain. The SDK decrypts it client-side using the user’s privateKey from ensureAccount. Call this after every operation to reflect the latest state. Add this function to your hook:

const fetchBalances = async () => {
  if (!client || !signer || !userKeys) return;
  try {
    const address = await signer.getAddress();

    // Decrypt the confidential balance using the user's HE private key
    const confidentialBalance = await client.getConfidentialBalance(
      address, // string the user's wallet address
      userKeys.privateKey, // string the HE private key from ensureAccount
      config.tokenAddress // string the ERC20 token contract address
    );

    // confidentialBalance.amount      BigInt: total of available + pending
    // confidentialBalance.available  { amount: BigInt, ciphertext: string }
    // confidentialBalance.pending    { amount: BigInt, ciphertext: string }

    // Also fetch the public ERC20 balance
    const publicBalance = await client.getPublicBalance(
      address,
      config.tokenAddress
    );

    setBalances({
      confidential: ethers.formatUnits(
        confidentialBalance.amount,
        tokenDecimals
      ),
      public: ethers.formatUnits(publicBalance, tokenDecimals),
      native: '0', // fetch native ETH separately if needed
    });
  } catch (e: any) {
    // Balance fetch errors are non-blocking don't surface them as UI errors
    console.error('Balance fetch failed:', e.message);
  }
};

Parameters for client.getConfidentialBalance:

Parameter	Type	Description
`address`	`string`	The user’s wallet address
`privateKey`	`string`	The HE private key returned by `ensureAccount`
`tokenAddress`	`string`	The ERC20 token contract address

Return fields:

Field	Type	Description
`amount`	`BigInt`	Total balance = available + pending combined
`available`	`{ amount: BigInt, ciphertext: string }`	Settled, spendable balance
`pending`	`{ amount: BigInt, ciphertext: string }`	Incoming balance not yet settled

available is what can be transferred or withdrawn immediately. pending represents amounts that have been deposited but are still finalizing onchain after finalization, pending becomes available. For most display purposes, show amount (the total) and optionally break it down into available and pending.

5.8 Finish the Hook

Wire up balance polling and export everything. Add this to the bottom of the hook, just before the closing return:

// Poll balances every 10 seconds when keys are available
useEffect(() => {
  if (!userKeys) return;
  fetchBalances();
  const interval = setInterval(fetchBalances, 10_000);
  return () => clearInterval(interval);
}, [userKeys]);

return {
  signer,
  userKeys,
  balances,
  loading,
  error,
  tokenSymbol,
  ensureAccount,
  confidentialDeposit,
  confidentialTransfer,
  withdraw,
};

The hook is now complete. You can see the complete implementation here: app/hooks/useConfidentialClient.ts Components import it like this:

const {
  signer,
  userKeys,
  balances, // { public: string, confidential: string, native: string }
  loading,
  error,
  tokenSymbol,
  ensureAccount,
  confidentialDeposit,
  confidentialTransfer,
  withdraw,
} = useConfidentialClient();

You can see the complete implementation of this hook here: app/hooks/useConfidentialClient.ts

Step 6: Building the UI Step by Step

The UI is a single page component at app/page.tsx. This section builds it piece by piece in the same order as the hook connect, initialize, deposit, withdraw, transfer. Start with the skeleton:

// app/page.tsx
'use client';

import { usePrivy } from '@privy-io/react-auth';
import { useState } from 'react';
import { useConfidentialClient } from './hooks/useConfidentialClient';

export default function Home() {
  const { login, logout, authenticated, user } = usePrivy();
  const {
    userKeys,
    balances,
    loading,
    error,
    tokenSymbol,
    ensureAccount,
    confidentialDeposit,
    confidentialTransfer,
    withdraw,
  } = useConfidentialClient();

  // Local form state added in the sections below

  return (
    <main className="min-h-screen bg-gray-50 p-8">
      <div className="max-w-lg mx-auto space-y-6">
        {/* Sections added below */}
      </div>
    </main>
  );
}

6.1 Connect Wallet

The first thing the user sees is a connect button. Show it when unauthenticated, and swap it for a disconnect button and the user’s wallet address once connected. Add this block inside <main>:

{
  /* Connect / Disconnect */
}
<div className="bg-white rounded-xl p-6 shadow-sm">
  <h1 className="text-xl font-semibold mb-4">Stabletrust Demo</h1>

  {!authenticated ? (
    <button
      onClick={login}
      className="w-full bg-black text-white py-2 rounded-lg font-medium hover:bg-gray-800"
    >
      Connect Wallet
    </button>
  ) : (
    <div className="flex items-center justify-between">
      <span className="text-sm text-gray-500 truncate">
        {user?.wallet?.address}
      </span>
      <button
        onClick={logout}
        className="text-sm text-red-500 hover:text-red-700"
      >
        Disconnect
      </button>
    </div>
  )}
</div>;

Privy’s login() opens its built-in modal. user?.wallet?.address is the connected address it only exists after authentication, so the optional chain prevents errors during the pre-auth render.

6.2 Initialize Confidential Account

Once connected, the user must initialize their confidential account before any other action is possible. Show this block only when authenticated but userKeys is still null. Add this block after the connect section:

{
  /* Initialize Account */
}
{
  authenticated && !userKeys && (
    <div className="bg-white rounded-xl p-6 shadow-sm">
      <h2 className="font-semibold mb-2">Initialize Confidential Account</h2>
      <p className="text-sm text-gray-500 mb-4">
        This creates your encrypted account onchain. It takes about 45 seconds
        and requires one wallet signature.
      </p>
      <button
        onClick={ensureAccount}
        disabled={loading}
        className="w-full bg-blue-600 text-white py-2 rounded-lg font-medium
                 hover:bg-blue-700 disabled:opacity-50"
      >
        {loading ? 'Initializing... (~45s)' : 'Initialize Account'}
      </button>
    </div>
  );
}

ensureAccount comes directly from the hook. loading is set to true by the hook for the duration of the call, so the button disables automatically while the transaction is processing.

6.3 Balance Display

Once userKeys exists, show the user’s public and confidential balances at the top of the action area. These values are refreshed automatically by the hook’s 10-second polling interval and after each operation. Add this block after the initialize section:

{
  /* Balance Display */
}
{
  userKeys && (
    <div className="bg-white rounded-xl p-6 shadow-sm">
      <h2 className="font-semibold mb-4">Balances</h2>
      <div className="grid grid-cols-2 gap-4">
        <div className="bg-gray-50 rounded-lg p-4">
          <p className="text-xs text-gray-400 mb-1">Public</p>
          <p className="text-lg font-mono font-semibold">
            {balances.public}{' '}
            <span className="text-sm font-normal">{tokenSymbol}</span>
          </p>
        </div>
        <div className="bg-blue-50 rounded-lg p-4">
          <p className="text-xs text-gray-400 mb-1">Confidential</p>
          <p className="text-lg font-mono font-semibold">
            {balances.confidential}{' '}
            <span className="text-sm font-normal">{tokenSymbol}</span>
          </p>
        </div>
      </div>
    </div>
  );
}

balances.public and balances.confidential are already formatted as human-readable strings by the hook (via ethers.formatUnits) no conversion needed here.

6.4 Deposit Form

The deposit form moves tokens from the public balance into the confidential layer. Add this state to the top of the component alongside the other state declarations:

const [depositAmount, setDepositAmount] = useState('');

Then add this block after the balance display:

{
  /* Deposit */
}
{
  userKeys && (
    <div className="bg-white rounded-xl p-6 shadow-sm">
      <h2 className="font-semibold mb-4">Deposit</h2>
      <p className="text-sm text-gray-500 mb-3">
        Move tokens from your public balance into the encrypted layer.
      </p>
      <input
        type="number"
        placeholder={`Amount in ${tokenSymbol}`}
        value={depositAmount}
        onChange={(e) => setDepositAmount(e.target.value)}
        className="w-full border rounded-lg px-3 py-2 mb-3 text-sm"
      />
      <button
        onClick={async () => {
          await confidentialDeposit(depositAmount);
          setDepositAmount('');
        }}
        disabled={loading || !depositAmount}
        className="w-full bg-green-600 text-white py-2 rounded-lg font-medium
                 hover:bg-green-700 disabled:opacity-50"
      >
        {loading ? 'Processing...' : 'Deposit'}
      </button>
    </div>
  );
}

The input captures a human-readable amount (e.g. "10"). The hook’s confidentialDeposit function handles the ethers.parseUnits conversion internally, so you pass the raw string directly.

6.5 Withdraw Form

The withdraw form moves tokens from the confidential balance back to the public ERC20 balance. Add this state:

const [withdrawAmount, setWithdrawAmount] = useState('');

Then add this block:

{
  /* Withdraw */
}
{
  userKeys && (
    <div className="bg-white rounded-xl p-6 shadow-sm">
      <h2 className="font-semibold mb-4">Withdraw</h2>
      <p className="text-sm text-gray-500 mb-3">
        Move tokens from the encrypted layer back to your public balance.
      </p>
      <input
        type="number"
        placeholder={`Amount in ${tokenSymbol}`}
        value={withdrawAmount}
        onChange={(e) => setWithdrawAmount(e.target.value)}
        className="w-full border rounded-lg px-3 py-2 mb-3 text-sm"
      />
      <button
        onClick={async () => {
          await withdraw(withdrawAmount);
          setWithdrawAmount('');
        }}
        disabled={loading || !withdrawAmount}
        className="w-full bg-orange-600 text-white py-2 rounded-lg font-medium
                 hover:bg-orange-700 disabled:opacity-50"
      >
        {loading ? 'Processing...' : 'Withdraw'}
      </button>
    </div>
  );
}

6.6 Transfer Form

The transfer form sends tokens privately to another address. It requires a recipient address in addition to an amount. Add this state:

const [transferAmount, setTransferAmount] = useState('');
const [recipient, setRecipient] = useState('');

Then add this block:

{
  /* Transfer */
}
{
  userKeys && (
    <div className="bg-white rounded-xl p-6 shadow-sm">
      <h2 className="font-semibold mb-4">Transfer</h2>
      <p className="text-sm text-gray-500 mb-3">
        Send tokens privately. The recipient must have an initialized
        confidential account.
      </p>
      <input
        type="text"
        placeholder="Recipient address (0x...)"
        value={recipient}
        onChange={(e) => setRecipient(e.target.value)}
        className="w-full border rounded-lg px-3 py-2 mb-3 text-sm font-mono"
      />
      <input
        type="number"
        placeholder={`Amount in ${tokenSymbol}`}
        value={transferAmount}
        onChange={(e) => setTransferAmount(e.target.value)}
        className="w-full border rounded-lg px-3 py-2 mb-3 text-sm"
      />
      <button
        onClick={async () => {
          await confidentialTransfer(recipient, transferAmount);
          setTransferAmount('');
          setRecipient('');
        }}
        disabled={loading || !transferAmount || !recipient}
        className="w-full bg-purple-600 text-white py-2 rounded-lg font-medium
                 hover:bg-purple-700 disabled:opacity-50"
      >
        {loading ? 'Processing...' : 'Transfer Privately'}
      </button>
    </div>
  );
}

The button stays disabled until both recipient and transferAmount have values, preventing accidental empty submissions.

6.7 Error Display

Add a global error banner that surfaces errors from any hook operation. Place this at the bottom of the <main> content, after all the action blocks:

{
  /* Error Banner */
}
{
  error && (
    <div className="bg-red-50 border border-red-200 text-red-700 rounded-xl p-4 text-sm">
      <span className="font-medium">Error: </span>
      {error}
    </div>
  );
}

The error string is set by the hook when any operation throws. It resets to null at the start of each new operation, so stale errors clear automatically when the user retries. You can see the complete UI implementation here: app/page.tsx

Step 7: Run the Application

npm run dev

Open http://localhost:3000. Expected flow:

Connect Wallet

Click Connect Wallet - Privy opens a modal.

Initialize Confidential Account

Click Initialize Confidential Account - the wallet prompts a signature. Wait approximately 45 seconds for onchain finalization.

Account becomes active

The balance display and action forms appear once the account is active.

Deposit, Withdraw, Transfer

Deposit moves tokens from your public balance into the encrypted layer, Withdraw moves them back to your public ERC20 balance, and Transfer sends them privately to another address (recipient must have an initialized account).

Ensure your wallet has test ETH on Base Sepolia for gas. You can get test ETH from the Base Sepolia faucet.

Architecture

The cryptographic design and system layers behind confidential transfers.

Stabletrust

The browser-based interface for confidential stablecoins and transfers.

Confidential Transfers

How the core confidential operations work end to end.

Common Errors

Troubleshoot errors returned by the SDK.

Get Started

Confidential Transfers

Protected Execution

Confidential Intelligence

Resources

Building an App with the SDK

Stabletrust SDK Demo

What You Are Building

Prerequisites

Step 1: Create the Next.js Application

Step 2: Install Dependencies

Step 3: Environment Variables

Step 4: Add the Privy Provider

Step 5: Building the Hook, Step by Step

5.1 Initialize the SDK Client

5.2 Wrap the Privy Wallet into an Ethers Signer

5.3 Initialize the Confidential Account

5.4 Deposit: Move Tokens into the Confidential Layer

5.5 Withdraw: Move Tokens Back to Public

5.6 Transfer Send Tokens Privately

5.7 Fetch the Confidential Balance

5.8 Finish the Hook

Step 6: Building the UI Step by Step

6.1 Connect Wallet

6.2 Initialize Confidential Account

6.3 Balance Display

6.4 Deposit Form

6.5 Withdraw Form

6.6 Transfer Form

6.7 Error Display

Step 7: Run the Application

Further Reading

Architecture

Stabletrust

Confidential Transfers

Common Errors

Stabletrust SDK Demo

​What You Are Building

​Prerequisites

​Step 1: Create the Next.js Application

​Step 2: Install Dependencies

​Step 3: Environment Variables

​Step 4: Add the Privy Provider

​Step 5: Building the Hook, Step by Step

​5.1 Initialize the SDK Client

​5.2 Wrap the Privy Wallet into an Ethers Signer

​5.3 Initialize the Confidential Account

​5.4 Deposit: Move Tokens into the Confidential Layer

​5.5 Withdraw: Move Tokens Back to Public

​5.6 Transfer Send Tokens Privately

​5.7 Fetch the Confidential Balance

​5.8 Finish the Hook

​Step 6: Building the UI Step by Step

​6.1 Connect Wallet

​6.2 Initialize Confidential Account

​6.3 Balance Display

​6.4 Deposit Form

​6.5 Withdraw Form

​6.6 Transfer Form

​6.7 Error Display

​Step 7: Run the Application

​Further Reading

Architecture

Stabletrust

Confidential Transfers

Common Errors

What You Are Building

Prerequisites

Step 1: Create the Next.js Application

Step 2: Install Dependencies

Step 3: Environment Variables

Step 4: Add the Privy Provider

Step 5: Building the Hook, Step by Step

5.1 Initialize the SDK Client

5.2 Wrap the Privy Wallet into an Ethers Signer

5.3 Initialize the Confidential Account

5.4 Deposit: Move Tokens into the Confidential Layer

5.5 Withdraw: Move Tokens Back to Public

5.6 Transfer Send Tokens Privately

5.7 Fetch the Confidential Balance

5.8 Finish the Hook

Step 6: Building the UI Step by Step

6.1 Connect Wallet

6.2 Initialize Confidential Account

6.3 Balance Display

6.4 Deposit Form

6.5 Withdraw Form

6.6 Transfer Form

6.7 Error Display

Step 7: Run the Application

Further Reading