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Integrate with Layer Leap

Overview​

Layer Leap is a protocol that enables users to bridge ETH and ERC-20 tokens directly from Ethereum to Arbitrum chains in a single transaction. This significantly improves user experience by eliminating the need for intermediate bridging steps.

Key benefits​

  • For users: Bridge tokens from Ethereum to any Arbitrum chain with a single transaction
  • For developers: Seamlessly onboard users to your Arbitrum chain directly from Ethereum

How it works​

Layer Leap uses a system of contracts to coordinate token transfers across multiple layers:

  1. L1Teleporter (on Ethereum): Entry point for token transfers
  2. L2ForwarderFactory (on Arbitrum One/Nova): Creates deterministic L2Forwarder contracts
  3. L2Forwarder (on Arbitrum One/Nova): Handles the final transfer to the Arbitrum chain

Technical architecture​

Layer Leap leverages two key mechanisms:

  1. For ERC-20 tokens: The Teleport Contracts coordinate transfers through the canonical token bridges of both the parent chain and the Arbitrum chain
  2. For ETH: A "double retryable" approach, where a retryable ticket creates another retryable ticket to complete the cross-chain transfer

Requirements​

Layer Leap currently supports Arbitrum chains with the following characteristics:

  • Built on top of an Arbitrum Layer 2 (Arbitrum One or Nova)
  • Using ETH as the gas token
  • The parent chain must be an Arbitrum chain due to reliance on retryable tickets.

Support for Arbitrum chains with custom gas tokens is planned for future releases.

Implementation guide​

Option 1: Integrate with Arbitrum bridge UI​

If you want your Arbitrum chain to appear on the Arbitrum bridge UI with Layer Leap support:

  1. If your chain is not yet on the Arbitrum bridge, submit a request using this GitHub template
  2. Request Layer Leap activation using this GitHub template

Option 2: Custom integration​

To integrate Layer Leap into your custom bridge UI:

  1. Set up infrastructure

    • Ensure your Arbitrum chain is properly configured
    • Deploy and configure the necessary components

  2. Implement the bridging flow

    The simplest implementation uses the Arbitrum SDK (Erc20L1L3Bridger from @arbitrum/sdk):

import { Erc20L1L3Bridger } from '@arbitrum/sdk';

// Create an L1-L3 bridger instance
const l1l3Bridger = new Erc20L1L3Bridger(l3Network);

// Initiate the teleport
const result = await l1l3Bridger.deposit({
  erc20ParentAddress: erc20Address, // Token address on L1
  amount, // Amount to bridge
  l1Signer, // Ethereum signer
  l2Provider, // Arbitrum L2 provider
  l3Provider, // Arbitrum chain provider
});
console.log(`Teleport initiated with hash: ${result.hash}`);

  1. Monitor and track teleports

    Track the status of a teleport:

import { Erc20L1L3Bridger } from '@arbitrum/sdk';

const l1l3Bridger = new Erc20L1L3Bridger(l3Network);
const status = await l1l3Bridger.getDepositStatus({
  l1TxHash,
  l1Provider,
  l2Provider,
  l3Provider,
});

console.log(`Teleport status: ${status}`);

Best practices​

  1. Retryable monitoring

    Run the Retryables Monitoring tool to track and redeem any failed retryables.

  2. Gas estimation

    Layer Leap requires sufficient gas to cover all steps across multiple chains. Conservative gas estimations are recommended.

  3. Error handling

    Implement proper error handling for each step of the teleport process, especially for handling potential failures at the L2 or L3 level.

Contract address​

ContractAddress
Arb One/Nova L1Teleporter0xCBd9c6e310D6AaDeF9F025f716284162F0158992

Demo examples​

You can see Layer Leap in action on the Arbitrum Bridge by bridging to:

Resources​