Anonymous Transfer Client

import { AnonymousTransferClient } from "@fairblock/stabletrust";
import { ethers } from "ethers";

const client = new AnonymousTransferClient({
  fairycloakUrl: "YOUR_FAIRYCLOAK_URL", // contact hello@fairblock.network
  chainId: 84532,
  rpcUrl: "https://sepolia.base.org",
  // apiKey: "YOUR_API_KEY",
});

const wallet = new ethers.Wallet(process.env.PRIVATE_KEY, client.provider);

// Account IDs are alphanumeric strings you choose (max 20 chars, case-sensitive).
// Your wallet address never appears on-chain — only this ID does.
const accountId = "alice123";

// Derive a deterministic ElGamal keypair from wallet + accountId.
// Re-derive from the same inputs at any time to recover it.
const keys = await client.deriveAnonymousKeys(wallet, accountId);

// Create the account. Idempotent — safe to call on every startup.
// The relay submits the transaction and pays gas.
const { created } = await client.ensureAnonymousAccount(
  wallet,
  accountId,
  keys.publicKey,
);

// Transfers deduct a small ERC-20 fee from a per-account prepaid reserve.
const feeToken  = await client.getFeeToken();
const feeAmount = await client.getFeeAmount();
const feeBal    = await client.getPrepaidFeeBalance(accountId, feeToken);

if (feeBal < feeAmount) {
  const result = await client.depositFees(wallet, accountId, feeAmount * 10n);
  await client.waitForRequest(result.request_id);
}

const tokenAddress  = "0x036CbD53842c5426634e7929541eC2318f3dCF7e";
const tokenDecimals = 6;

// The only operation where your wallet pays gas.
// ERC-20 approval is handled automatically.
const result = await client.deposit(
  wallet,
  accountId,
  tokenAddress,
  ethers.parseUnits("10", tokenDecimals),
);
await client.waitForRequest(result.request_id);

const balance = await client.getBalance(accountId, tokenAddress, keys.privateKey);
// Decryption happens client-side. Your private key never leaves your device.

// Amounts are in contract scale (rawAmount × 100 / 10^decimals).
// For a 6-decimal token: 1000 = 10 tokens.
console.log("Available:", balance.available);
console.log("Pending:  ", balance.pending);

// To a public address
const result = await client.transferToPublic(wallet, accountId, {
  recipient:         "0xRecipientAddress",
  token:             tokenAddress,
  elGamalPrivateKey: keys.privateKey,
  amount:            ethers.parseUnits("3", tokenDecimals),
});
await client.waitForRequest(result.request_id);

// To another anonymous account
const result2 = await client.transferToAnonymous(wallet, accountId, {
  recipientId:       "bob456",
  token:             tokenAddress,
  elGamalPrivateKey: keys.privateKey,
  amount:            ethers.parseUnits("3", tokenDecimals),
});
await client.waitForRequest(result2.request_id);

// The recipient must call applyPending() before spending received funds.
await client.applyPending(recipientWallet, "bob456");

const result = await client.withdraw(wallet, accountId, {
  destination:       wallet.address,
  token:             tokenAddress,
  plainAmount:       ethers.parseUnits("2", tokenDecimals),
  elGamalPrivateKey: keys.privateKey,
});
await client.waitForRequest(result.request_id);