BTC deposit addresses

This section explains how to generate and reuse BTC deposit addresses.

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Overview

When staking BTC, the SDK generates a unique deposit address. These addresses are:

• Chain-specific — Bound to a destination chain, partnerId and recipient

• Reusable — Can receive multiple deposits

• Signature-bound — Tied to the authorization signature (for Ethereum Mainnet)

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Generating a Deposit Address

import { createLombardSDK, Chain, AssetId } from '@lombard.finance/sdk';
import { config } from './lib/lombard';

const sdk = createLombardSDK(config);

const stake = sdk.chain.btc.stake({
  destChain: Chain.ETHEREUM,
  assetOut: AssetId.LBTC,
});

await stake.prepare({
  amount: '0.1',
  recipient: '0x1234567890abcdef1234567890abcdef12345678',
});

await stake.authorize();

const depositAddress = await stake.generateDepositAddress();
// depositAddress: 'bc1q...'

---

Checking for Existing Address

Use the API to check if a deposit address already exists.

import { createLombardSDK, ChainId } from '@lombard.finance/sdk';
import { config } from './lib/lombard';

const sdk = createLombardSDK(config);

try {
  const address = await sdk.api.depositAddress(
    '0x1234567890abcdef1234567890abcdef12345678',
    ChainId.ethereum,
    // Optional override
    {
      partnerId: 'test', // Uses partnerId from sdk config
      token: Token.LBTC // defaults to Token.LBTC
    }
  );
  // Address exists: 'bc1q...'
} catch (error) {
  // No existing address - need to generate one
}

---

Reusing Addresses

Deposit addresses can receive multiple deposits. Each deposit is processed independently.

// First deposit
const depositAddress = await stake.generateDepositAddress();
// User sends 0.1 BTC

// Later, user can send more BTC to the same address
// No need to generate a new address

---

Address Expiration

BTC deposit addresses do not expire. However, fee authorization signatures for Ethereum Mainnet may expire after a defined period. When a signature expires, re-authorization is required before generating a new address.

---

Multiple Chains

Each destination chain requires its own deposit address.

// Ethereum deposit address
const ethStake = sdk.chain.btc.stake({
  destChain: Chain.ETHEREUM,
  assetOut: AssetId.LBTC,
});
await ethStake.prepare({ amount: '0.1', recipient: '0x...' });
await ethStake.authorize();
const ethAddress = await ethStake.generateDepositAddress();

// Base deposit address (different)
const baseStake = sdk.chain.btc.stake({
  destChain: Chain.BASE,
  assetOut: AssetId.LBTC,
});
await baseStake.prepare({ amount: '0.1', recipient: '0x...' });
await baseStake.authorize();
const baseAddress = await baseStake.generateDepositAddress();