Using the BOBA Token Bridge Between L1s

Learn more about the BOBA Token Bridge Between L1s

The BOBA token bridge functionality provides a method for the BOBA token to be deposited and locked on Ethereum in order to mint the same amount of an equivalent representation token on Alt L1s. This process is known as "bridging a token", e.g. depositing 100 BOBA to the bridge contract on Ethereum in exchange for 100 BOBA on an Alt L1 and also the reverse - withdrawing 100 BOBA on an Alt L1 in exchange for the same amount on Ethereum, in which case the BOBA token on the Alt L1 is burned in order to release the funds locked on Ethereum.

The BOBA Token Bridge is composed of two main contracts the EthBridge (opens new window)(for Ethereum) and the AltL1Bridge (opens new window)(for Alt L1s).

Here we'll go over the basics of using this bridge to move BOBA tokens between Layer 1s.

For normal users, bridging can be accomplished simply via the Light Bridge.

For developers, you can interact with EthBridge (opens new window) to deposit BOBA tokens from Ethereum to Alt L1s.

const PRIVATE_KEY, L1_NODE_WEB3_URL, DEPOSIT_AMOUNT, BOBA_TOEKN_ADDRESS_ON_ETHEREUM, BOBA_TOKEN_ADDRESS_ON_ALT_L1, ALT_L1_LARYER_ZERO_CHAIN_ID, ETHEREUM_LARYER_ZERO_CONTRACT, PROXY__ETHEREUM_BRIDGE

const L1Provider = new ethers.providers.StaticJsonRpcProvider(L1_NODE_WEB3_URL)
const L1Wallet = new ethers.Wallet(PRIVATE_KEY).connect(L2Provider)

const Proxy__EthBridge = new ethers.Contract(
  PROXY__ETHEREUM_BRIDGE,
  EthBridgeJson.abi,
  L1Wallet,
);

const EthBOBA = new ethers.Contract(
  BOBA_TOEKN_ADDRESS_ON_ETHEREUM,
  BobaTokenJson.abi,
  L1Wallet,
);

const ETHLayzerZeroEndpoint = new ethers.Contract(
  ETHEREUM_LARYER_ZERO_CONTRACT,
  LZEndpointMockJson.abi,
  L1Wallet,
);

// approve boba
const approveTx = await EthBOBA.approve(Proxy__EthBridge.address, ethers.utils.parseEther(DEPOSIT_AMOUNT));
await approveTx.wait();
console.log(`-> Approved ${DEPOSIT_AMOUNT} BOBA tokens for transfer`);

// estimate fee
let payload = ethers.utils.defaultAbiCoder.encode(
  ["address", "address", "address", "address", "uint256", "bytes"],
  [
    BOBA_TOEKN_ADDRESS_ON_ETHEREUM,
    BOBA_TOKEN_ADDRESS_ON_ALT_L1,
    L1Wallet.address,
    Target_Wallet_Address_On_Alt_L1,
    ethers.utils.parseEther(DEPOSIT_AMOUNT.toString()),
    '0x',
  ]
);

let estimatedFee = await ETHLayzerZeroEndpoint.estimateFees(
  ALT_L1_LARYER_ZERO_CHAIN_ID,
  PROXY__ETHEREUM_BRIDGE.address,
  payload,
  false,
  '0x',
);
console.log(`!!! Estimated fee: ${ethers.utils.formatEther(estimatedFee._nativeFee)}!!!`);

await Proxy__EthBridge.depositERC20To(
  EthBOBA.address,
  BOBA_TOKEN_ADDRESS_ON_ALT_L1,
  ethers.utils.parseEther(DEPOSIT_AMOUNT.toString()),
  ethers.constants.AddressZero,
  '0x', // adapterParams
  '0x',
  { value: estimatedFee._nativeFee }
);
console.log(`-> Sent ${DEPOSIT_AMOUNT} BOBA tokens to the bridge contract....`);

Example code can be found here: bridgeFromEthereumToAltL.js.

For normal users, bridging can be accomplished simply via the Light Bridge.

For developers, you can interact with AltL1Bridge (opens new window) to deposit BOBA tokens from Alt L1 to Ethereum.

const PRIVATE_KEY, L1_NODE_WEB3_URL, DEPOSIT_AMOUNT, BOBA_TOEKN_ADDRESS_ON_ETHEREUM, BOBA_TOKEN_ADDRESS_ON_ALT_L1, ETH_LARYER_ZERO_CHAIN_ID, Alt_L1_LARYER_ZERO_CONTRACT, PROXY__ALT_L1_BRIDGE

const L1Provider = new ethers.providers.StaticJsonRpcProvider(L1_NODE_WEB3_URL)
const L1Wallet = new ethers.Wallet(PRIVATE_KEY).connect(L2Provider)

const Proxy__AltL1Bridge = new ethers.Contract(
  PROXY__ALT_L1_BRIDGE,
  AltBridgeJson.abi,
  L1Wallet,
);

const AltL1BOBA = new ethers.Contract(
  BOBA_TOEKN_ADDRESS_ON_Alt_L1,
  BobaTokenJson.abi,
  L1Wallet,
);

const AltL1LayzerZeroEndpoint = new ethers.Contract(
  Alt_L1_LARYER_ZERO_CONTRACT,
  LZEndpointMockJson.abi,
  L1Wallet,
);

// approve boba
const approveTx = await AltL1BOBA.approve(Proxy__AltL1Bridge.address, ethers.utils.parseEther(DEPOSIT_AMOUNT));
await approveTx.wait();
console.log(`-> Approved ${DEPOSIT_AMOUNT} BOBA tokens for transfer`);

// estimate fee
let payload = ethers.utils.defaultAbiCoder.encode(
  ["address", "address", "address", "address", "uint256", "bytes"],
  [
    BOBA_TOKEN_ADDRESS_ON_ETHREUM,
    BOBA_TOKEN_ADDRESS_ON_ALT_L1,
    L1Wallet.address,
    Target_Wallet_Address_On_ETHEREUM,
    ethers.utils.parseEther(DEPOSIT_AMOUNT.toString()),
    '0x',
  ]
);

let estimatedFee = await AltL1LayzerZeroEndpoint.estimateFees(
  ETH_LARYER_ZERO_CHAIN_ID,
  Proxy__AltL1Bridge.address,
  payload,
  false,
  '0x',
);
console.log(`!!! Estimated fee: ${ethers.utils.formatEther(estimatedFee._nativeFee)}!!!`);

await Proxy__AltL1Bridge.depositERC20To(
  AltL1BOBA.address,
  BOBA_TOKEN_ADDRESS_ON_ETHEREUM,
  ethers.utils.parseEther(DEPOSIT_AMOUNT.toString()),
  ethers.constants.AddressZero,
  '0x', // adapterParams
  '0x',
  { value: estimatedFee._nativeFee }
);
console.log(`-> Sent ${DEPOSIT_AMOUNT} BOBA tokens to the bridge contract....`);

Mainnet

Layer Zero Contracts

Network	Layer Zero Contract Address	Chain ID
Ethereum	0x66A71Dcef29A0fFBDBE3c6a460a3B5BC225Cd675	101
BNB	0x3c2269811836af69497E5F486A85D7316753cf62	102

Ethereum Contracts

Contract Name	Contract Address
Proxy__EthBridgeToBNB	0x1A36E24D61BC1aDa68C21C2Da1aD53EaB8E03e55
L1_BOBA	0x42bBFa2e77757C645eeaAd1655E0911a7553Efbc

BNB Contract

Contract Name	Contract Address
Proxy__BNBBridgeToEth	0x819FF4d9215C9dAC76f5eC676b1355973157eBBa
L1_BOBA	0xE0DB679377A0F5Ae2BaE485DE475c9e1d8A4607D