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Forwarding Address for Tether WDK

· 4 min read
Marc
Marc

Candide's Forwarding Address now works with Tether's Wallet Development Kit (WDK). The module, @candidelabs/wdk-protocol-sda-candide, lets wallets offer the same deposit address across supported EVM chains and receive the funds on a chosen destination chain.

A user withdrawing USDT from an exchange can send it over any supported EVM chain to the same address. The funds are forwarded to their account on the destination chain. Deposits can also come from the destination chain itself, and each supported token arrives as its equivalent there.

The address is a self-custodial contract. The relayer can only forward funds to the configured recipient; it has no withdrawal rights. The recipient can withdraw directly at any time. You can also configure a company recovery wallet to recover stuck funds after a timelock. This is useful when a user deposits from an exchange and has no key on the source chain.

Using the module​

Version 1.0.0-beta.1 is available on npm. It implements WDK's Smart Deposit Address (SDA) interface, ISdaProtocol from @tetherto/wdk-wallet. The module runs on Node.js 20+ and includes a Bare entry point.

npm install @candidelabs/wdk-protocol-sda-candide
import CandideForwardingProtocol from '@candidelabs/wdk-protocol-sda-candide'

const sda = new CandideForwardingProtocol(undefined, {
  apiUrl: process.env.CANDIDE_FORWARDING_API_URL,             // from the Candide dashboard
  policySecret: process.env.CANDIDE_FORWARDING_POLICY_SECRET, // to create, renew, or recover; server-side only
  recoveryWithdrawer: '0xYourCompanyRecoveryWallet'          // recommended if users deposit from exchanges
})

// Accept deposits on Ethereum, Arbitrum, and Base; deliver to Arbitrum
const [deposit] = await sda.createDepositAddress({
  sourceChains: [1, 42161, 8453],
  destinationChain: 42161,
  destinationAddress: '0xRecipientOnArbitrum'
})

// Read the 20 most recent transfers for this address
const transfers = await sda.getTransfers(deposit.address, { limit: 20 })

Keep the policy secret on your backend. It is needed to create an address, renew its monitoring, and recover a lapsed one, so createDepositAddress, renewDepositAddress, and recoverDepositAddress run there. The wallet client can fetch routes, quotes, minimum amounts, and transfer history, and derive addresses without a secret.

Address verification​

The SDK derives each deposit address locally using CREATE2. It uses pinned factory and beacon addresses and proxy bytecode, together with the recipient, recovery withdrawer, destination chain, and salt. It then checks the result against the address returned by the API and throws if they differ. You can also derive an address without activating it using deriveDepositAddress. It fetches the relayer address from the API once, unless you pin deployParams.allowedRelayer in the config, in which case derivation runs fully offline.

Monitoring, routes, and fees​

Monitoring expires, so show the expiry alongside the deposit address and call renewDepositAddress whenever the user opens the deposit screen. Funds deposited after expiry remain at the address until monitoring is renewed, then forwarding resumes.

Available routes depend on the source chain, so call getSupportedRoutes({ sourceChain, destinationChain }) for each source chain you accept, instead of hardcoding chains or tokens.

Quotes are estimates and include the relayer and bridge fees. Pass the activated depositAddress to quoteDeposit to get a quote that reflects your policy; sponsored: true means the policy is expected to pay the fees. When sponsorship is on and the policy's balance or limits cannot cover a fee, the deposit is held rather than forwarded, so keep an eye on the policy balance in the dashboard.

You can get your API URL and policy secret from the Candide dashboard. For the full integration details:

Building with a coding agent​

If you use Claude Code, install the Candide skills. The forwarding-address skill teaches the agent how forwarding addresses work: activation and renewal, routes and minimums, fee estimates, transfer tracking, and the recovery withdrawer.

/plugin marketplace add candidelabs/skills
/plugin install candide@candide

For Codex CLI, run npx -y github:candidelabs/skills. Other harnesses are covered in the candidelabs/skills repo.

~ Marc