BTC.b to LBTC and LBTC to BTC.b Swaps

This guide explains converting between BTC.b and LBTC through smart contract interactions via block explorers. All amounts are in satoshis (1 BTC = 100,000,000 satoshis).

Converting BTC.b to LBTC

Step 1: Initiate Deposit via Asset Router

Access the Asset Router contract on Etherscan:

Contract: 0x9eCe5fB1aB62d9075c4ec814b321e24D8EA021ac

URL: https://etherscan.io/address/0x9eCe5fB1aB62d9075c4ec814b321e24D8EA021ac#writeProxyContract

1. Connect your Web3 wallet containing BTC.b
2. Locate function 18: deposit (0x8340f549)
3. Enter parameters:
   • fromAddress: your wallet address
   • toToken: 0x8236a87084f8B84306f72007F36F2618A5634494 (LBTC address)
   • amount: satoshi amount to convert
4. Submit the transaction

Step 2: Retrieve Authorization Data

Query the API endpoint:

https://mainnet.prod.lombard.finance/api/v1/address/native-deposits/{address}

Replace {address} with your wallet address. Wait until notarization_status shows "NOTARIZATION_STATUS_SESSION_APPROVED", then extract the raw_payload and proof fields.

Step 3: Mint LBTC

Access the LBTC contract on Etherscan:

Contract: 0x8236a87084f8B84306f72007F36F2618A5634494

URL: https://etherscan.io/address/0x8236a87084f8B84306f72007F36F2618A5634494#writeProxyContract

1. Connect Web3 wallet
2. Use function 21: mint (0x6bc63893)
3. Paste the payload and proof from Step 2
4. Execute the transaction to receive minted LBTC

Converting LBTC to BTC.b

Step 1: Initiate Redemption

Access the LBTC contract on Katanascan:

Contract: 0xecAc9C5F704e954931349Da37F60E39f515c11c1

URL: https://katanascan.com/address/0xecAc9C5F704e954931349Da37F60E39f515c11c1#writeProxyContract

1. Connect Web3 wallet
2. Use function 25: redeem (0xdb006a75)
3. Enter the LBTC amount in satoshis
4. Submit the transaction

Step 2: Retrieve Authorization Data

Query the endpoint:

https://mainnet.prod.lombard.finance/api/v1/address/unstakes/{address}?show_redeems=true&to_native=true

Note: Unstaking requires up to 8 days. Wait for notarization_status to show approved, then extract the payload and proof.

Step 3: Mint BTC.b

Access the BTC.b contract on Katanascan:

Contract: 0xb0f70c0bd6fd87dbeb7c10dc692a2a6106817072

URL: https://katanascan.com/address/0xb0f70c0bd6fd87dbeb7c10dc692a2a6106817072#writeProxyContract

1. Connect Web3 wallet
2. Use function 21: mintV1 (0x8307f738)
3. Submit the payload and proof from Step 2
4. Execute the transaction to receive BTC.b