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    Using the Bridge

    The Liberty Chain Bridge is the canonical gateway for moving assets between Ethereum Sepolia (Layer 1) and Liberty Chain (Layer 2). Built on the standard OP Stack bridge architecture, it inherits the same battle-tested security model used by Optimism and other OP Stack chains. The bridge supports native ETH as well as ERC-20 tokens through the standard bridge contracts.

    You can access the bridge at https://chain.lcx.com/bridge.

    How Deposits Work (L1 → L2)

    A deposit moves assets from Ethereum Sepolia to Liberty Chain. When you initiate a deposit, your assets are locked in the L1 bridge contract and a corresponding amount is minted or released on Liberty Chain. Deposits are relatively fast because the sequencer monitors L1 for deposit transactions and includes them in L2 blocks as soon as they are confirmed on L1.

    Typical deposit time: 1 to 3 minutes. This includes L1 confirmation time plus the sequencer picking up the deposit event and including it in an L2 block.

    Deposits Are Fast

    Unlike withdrawals, deposits from L1 to L2 complete in just a few minutes. If you need assets on Liberty Chain quickly, depositing through the bridge is the most straightforward approach.

    How Withdrawals Work (L2 → L1)

    A withdrawal moves assets from Liberty Chain back to Ethereum Sepolia. Withdrawals follow a multi-step process that includes a mandatory challenge period. This challenge period exists so that anyone can submit a fault proof if the withdrawal is based on an invalid state transition, ensuring the security of bridged assets.

    The withdrawal process involves three phases:

    1. Initiate — Submit the withdrawal transaction on Liberty Chain (L2). This burns or locks your tokens on L2.
    2. Challenge period — Wait approximately 7 days for the fault proof challenge window to pass. During this time, anyone can dispute the withdrawal if the underlying state is invalid.
    3. Finalize — After the challenge period ends, submit a finalization transaction on L1 to claim your assets.

    7-Day Withdrawal Period

    Withdrawals from Liberty Chain to Ethereum require a 7-day challenge period before they can be finalized. This is a fundamental security mechanism of the OP Stack and cannot be bypassed. Plan accordingly when moving assets from L2 back to L1.

    Step-by-Step: Depositing Assets (L1 → L2)

    1. Connect your wallet — Navigate to the bridge interface and connect your wallet. Make sure your wallet is set to Ethereum Sepolia.
    2. Select the deposit direction — Ensure the bridge is set to transfer from Sepolia (L1) to Liberty Chain (L2).
    3. Enter the amount — Specify how much ETH (or which ERC-20 token and amount) you want to deposit. Make sure you retain enough Sepolia ETH to cover the L1 gas fee for the deposit transaction.
    4. Approve the transaction — For ERC-20 tokens, you may need to approve the bridge contract to spend your tokens before depositing. ETH deposits do not require a separate approval step.
    5. Confirm and wait — Submit the deposit transaction and wait for it to be confirmed on L1. Within 1 to 3 minutes, your assets will appear on Liberty Chain.

    You can verify your deposit by checking your address on the Liberty Chain Block Explorer.

    Step-by-Step: Withdrawing Assets (L2 → L1)

    1. Initiate the withdrawal on L2 — Open the bridge interface, switch the direction to Liberty Chain (L2) → Sepolia (L1), enter the amount, and submit the transaction.
    2. Wait for the challenge period — After your withdrawal transaction is confirmed on L2, a 7-day challenge window begins. You do not need to take any action during this time. The bridge interface will show the remaining time.
    3. Prove the withdrawal — Once the L2 output containing your withdrawal is published to L1, you can submit a proof transaction. The bridge interface will prompt you when this step is available.
    4. Finalize on L1 — After the full challenge period has elapsed, return to the bridge interface and click "Finalize" to claim your assets on Ethereum Sepolia. This submits an L1 transaction that releases your funds.

    Supported Assets

    The Liberty Chain Bridge supports the following asset types:

    • ETH (native) — Bridge ETH directly between L1 and L2. On Liberty Chain, ETH is used as the native gas token just like on Ethereum.
    • ERC-20 tokens — Any standard ERC-20 token can be bridged via the standard bridge contracts. The first time a token is bridged, a corresponding representation is created on the destination chain.

    For questions about bridging specific tokens or for guidance on adding token support, refer to the Network Details page or reach out through the community channels.