Quickstart

Get your API key at hackathon-apikey.vercel.app.

Network

Unlink is live on Base Sepolia.

Resource	Value
Network	Base Sepolia
Chain ID	`84532`
API URL	`https://staging-api.unlink.xyz`
Pool Address	`0x647f9b99af97e4b79DD9Dd6de3b583236352f482`

Faucet

Get testnet tokens for development.

Base Sepolia faucet

Get testnet ETH for gas.

Prerequisites

Make sure you have:

Node.js v18 or later
A package manager (npm, pnpm, yarn, or bun)
A TypeScript project

Don't have a project yet?

mkdir my-app && cd my-app
npm init -y
npm install typescript tsx

Install

npm install @unlink-xyz/sdk viem

Create a client

createUnlink() returns a client bound to one Unlink account. Every operation (deposit, transfer, withdraw) acts on behalf of that account.

Server-side (Node.js)
Browser (viem)
Browser (ethers)

Use a private key and viem for backends, scripts, bots, or AI agents. In a multi-user setup, instantiate one client per user request.

import { createUnlink, unlinkAccount, unlinkEvm } from "@unlink-xyz/sdk";
import { createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { baseSepolia } from "viem/chains";

const evmAccount = privateKeyToAccount(
  process.env.EVM_PRIVATE_KEY as `0x${string}`,
);

const walletClient = createWalletClient({
  account: evmAccount,
  chain: baseSepolia,
  transport: http(process.env.RPC_URL),
});

const unlink = createUnlink({
  engineUrl: "https://staging-api.unlink.xyz",
  apiKey: process.env.UNLINK_API_KEY!,
  // BIP-39 mnemonic that derives the user's Unlink account keys.
  // Generate one with: npx @scure/bip39 or any BIP-39 library.
  // A different mnemonic produces a different Unlink account.
  account: unlinkAccount.fromMnemonic({
    mnemonic: process.env.UNLINK_MNEMONIC!,
  }),
  evm: unlinkEvm.fromViem({ walletClient }),
});

Connect to the user’s wallet via viem’s browser wallet client.

import { createUnlink, unlinkAccount, unlinkEvm } from "@unlink-xyz/sdk";
import { createWalletClient, custom } from "viem";
import { baseSepolia } from "viem/chains";

const [address] = await window.ethereum.request({
  method: "eth_requestAccounts",
});

const walletClient = createWalletClient({
  account: address,
  chain: baseSepolia,
  transport: custom(window.ethereum),
});

const unlink = createUnlink({
  engineUrl: "https://staging-api.unlink.xyz",
  apiKey: "your-api-key",
  // BIP-39 mnemonic that derives the user's Unlink account keys.
  // Your app must generate this on first use and persist it securely
  // (e.g. encrypted in localStorage or your backend).
  // A different mnemonic produces a different Unlink account.
  account: unlinkAccount.fromMnemonic({
    mnemonic: userMnemonic,
  }),
  evm: unlinkEvm.fromViem({ walletClient }),
});

Connect to the user’s wallet via MetaMask or any injected provider.

import { createUnlink, unlinkAccount, unlinkEvm } from "@unlink-xyz/sdk";
import { BrowserProvider } from "ethers";

const browserProvider = new BrowserProvider(window.ethereum);
const signer = await browserProvider.getSigner();

const unlink = createUnlink({
  engineUrl: "https://staging-api.unlink.xyz",
  apiKey: "your-api-key",
  // BIP-39 mnemonic that derives the user's Unlink account keys.
  // Your app must generate this on first use and persist it securely.
  account: unlinkAccount.fromMnemonic({
    mnemonic: userMnemonic,
  }),
  evm: unlinkEvm.fromEthers({ signer }),
});

Use unlinkAccount.fromSeed(...) or unlinkAccount.fromKeys(...) when you already manage seed material or raw account keys outside the SDK.What each piece does:

Concept	Role
`createWalletClient` (viem) / `BrowserProvider` (ethers)	Standard EVM wallet — signs on-chain transactions (deposits, approvals). Not Unlink-specific.
`unlinkAccount.fromMnemonic()`	Derives your Unlink account (private spending & viewing keys) from a BIP-39 mnemonic. A different mnemonic = a different Unlink identity.
`unlinkEvm.fromViem()` / `unlinkEvm.fromEthers()`	Bridges your EVM wallet into the SDK so Unlink can submit on-chain transactions on your behalf.
`createUnlink()`	Combines everything into a single client. Every SDK operation goes through this client.

Get your Unlink address

Your Unlink address (unlink1...) is your identity inside the privacy pool. Share it to receive private transfers — it does not reveal your EVM wallet.

const address = await unlink.getAddress();
console.log(address); // "unlink1..."

This address is deterministically derived from your mnemonic. The same mnemonic always produces the same address.

Get test tokens

Fund your Unlink account directly via the faucet. No EVM approval or gas needed.

const seeded = await unlink.faucet.requestPrivateTokens({
  token: "0x7501de8ea37a21e20e6e65947d2ecab0e9f061a7",
});

You can verify the balance arrived:

const { balances } = await unlink.getBalances();
console.log(balances);

See Faucet for other options like minting public ERC-20 tokens to an EVM wallet.

Transfer

Send tokens privately to another Unlink address. pollTransactionStatus polls until the transaction reaches a terminal state; see Utilities for options.

const transfer = await unlink.transfer({
  recipientAddress: "unlink1recipient...",
  token: "0x7501de8ea37a21e20e6e65947d2ecab0e9f061a7",
  amount: "250000000000000000",
});

const confirmed = await unlink.pollTransactionStatus(transfer.txId);

See Transfer for multi-recipient transfers.

Withdraw

Move tokens back to any EVM address:

const withdrawal = await unlink.withdraw({
  recipientEvmAddress: "0xRecipient",
  token: "0x7501de8ea37a21e20e6e65947d2ecab0e9f061a7",
  amount: "500000000000000000",
});

const confirmed = await unlink.pollTransactionStatus(withdrawal.txId);

See Withdraw for all parameters.

Going further

Deposit from an EVM wallet

To move ERC-20 tokens from an on-chain wallet into the unlink contract, use deposit(). This requires a one-time Permit2 approval per token and an EVM provider with publicClient for receipt polling.

import { createPublicClient, http } from "viem";
import { baseSepolia } from "viem/chains";

const publicClient = createPublicClient({
  chain: baseSepolia,
  transport: http(process.env.RPC_URL),
});

const approval = await unlink.ensureErc20Approval({
  token: "0x7501de8ea37a21e20e6e65947d2ecab0e9f061a7",
  amount: "1000000000000000000",
});

if (approval.status === "submitted") {
  await publicClient.waitForTransactionReceipt({
    hash: approval.txHash as `0x${string}`,
  });
}

const deposit = await unlink.deposit({
  token: "0x7501de8ea37a21e20e6e65947d2ecab0e9f061a7",
  amount: "1000000000000000000",
});

const confirmed = await unlink.pollTransactionStatus(deposit.txId);

See Deposit for the full parameter reference, approval helpers, and EVM provider setup.

Get Started

Build

Network

Faucet

Base Sepolia faucet

Prerequisites

Going further

Deposit from an EVM wallet

Get Started

Build

​Network

Faucet

Base Sepolia faucet

​Prerequisites

​Going further

​Deposit from an EVM wallet

Network

Prerequisites

Going further

Deposit from an EVM wallet