Mantle Bridge: How to Move Assets to Mantle Network

The Mantle bridge is the official smart contract system that moves ETH, MNT, and other tokens between Ethereum and Mantle Network, a Layer 2 chain running on a modified version of the OP Stack. Funds deposited to Mantle usually become accessible in minutes, while withdrawals, which once required a mandatory seven-day challenge period, now take a few hours after the transition to a validity-proving system.

The introduction of that system made a fundamental change to the basic logic and security model behind the bridge. Understanding this model makes it much easier to know what to expect when bridging to or from Mantle Network.

What Is Mantle Network?

Mantle Network is an Ethereum Layer 2 chain that originated from BitDAO, a decentralized organization holding one of the largest treasuries in the cryptocurrency world. BitDAO was voted into a rebrand that became Mantle Network, and MNT was chosen as its native token for paying gas fees and participating in governance.

The chain uses a fork of the OP Stack, the open-source system used by Optimism and other Layer 2s, which explains why there is much in common between Mantle and those networks when it comes to tooling and architecture.

What Is the Mantle Bridge?

The Mantle bridge is a system consisting of two smart contracts – one on Ethereum and one on Mantle Network – managing the locking, minting, burning, and releasing of assets when transferring them from one chain to another. A user interacts with this system through the official bridge interface, where he or she connects a wallet, chooses an asset and an amount, and selects the direction of movement.

Similar to other Layer 2 bridges, the Mantle bridge is asymmetric. When transferring funds from Ethereum to Mantle Network, the user experiences quick execution of the operation. When withdrawing assets from the Layer 2, however, the process takes longer because of the requirement to wait for the proof of the state's correctness.

How the Mantle Bridge Works

Depositing from Ethereum to Mantle

• The user submits a deposit transaction to the bridge contract on Ethereum, sending the asset they want to move.

• The bridge contract locks that asset on Ethereum.

• The bridge on Mantle Network receives the deposit and mints an equivalent balance of the asset to the user's address on Mantle Network.

• The balance becomes available within a few minutes after the transaction on Ethereum.

Withdrawing from Mantle to Ethereum

• The user initiates a withdrawal transaction on Mantle Network.

• The bridge contract on Mantle Network burns the asset.

• This creates a message recording the withdrawal, which needs to be included in a state update sent to Ethereum.

• A cryptographic proof of the state update's correctness is created and submitted to Ethereum for verification.

• Once the proof is verified, the user returns to the bridge interface to complete the withdrawal on Ethereum, paying an extra fee for this action.

From Optimistic Rollup to ZK Validity Proofs

During most of its existence, Mantle Network has been a regular optimistic rollup. All the transactions are assumed to be correct, and all the withdrawals have to wait for a seven-day challenge period for someone to report the fraud (the exact period may vary). This scheme is implemented by many OP Stack chains, such as Optimism and Base, as a way of protecting networks from malicious actors and ensuring transaction validity before executing them.

In 2025, Mantle Network adopted a solution called OP Succinct, which replaces the optimistic rollup method with ZK-validity proofs generated by Succinct's SP1 prover. This system proved to be more efficient in terms of reducing the time of withdrawals by creating a proof of the state's correctness before executing transactions on Ethereum. It reduced the time of withdrawal to six to twelve hours, depending on current network situation.

Data Availability and EigenDA

Unlike most other OP Stack rollups, Mantle Network uses the modular method of data availability, which means that transaction data is not always posted directly on Ethereum.

Instead, Mantle Network uses EigenDA, a data availability solution built on top of EigenLayer's restaking protocol, to store transaction data in a cheaper way. This modularity allows Mantle Network to charge lower fees than other OP Stack chains, though at the same time it makes data availability depend on EigenDA's own security guarantees, in addition to the security of Ethereum.

Bridge Security

All the assets being transferred to the Mantle Network via the official bridge are locked in a smart contract on Ethereum until they are either used to back the corresponding balance on Mantle or released back to a user through a completed withdrawal. Adoption of ZK-proofs made the withdrawal process more secure, since no withdrawal can be finalized without proving its correctness on Ethereum, whereas previously an invalid update could theoretically go unchallenged and be treated as valid.

The operator of Mantle Network, called a sequencer, is a centralized entity ordering transactions. This means day-to-day transaction ordering is not fully decentralized, which is a characteristic of most modern Layer 2 chains, despite the fact that transactions and their proofs are validated by Ethereum.

Supported Assets and Fees

The official Mantle bridge supports ETH and MNT directly, and a wide range of ERC-20 tokens mapped to Mantle Network. Depositing requires paying Ethereum gas, and interacting with Mantle Network afterward requires MNT for gas fees.

When withdrawing funds to Ethereum, the user has to spend additional MNT to initiate the withdrawal on Mantle Network, and additional ETH to execute the final step on Ethereum. The protocol itself doesn't impose an extra fee on top of those network fees.

Mantle Bridge Versus Third-Party Bridges

There are several third-party bridges supporting the transfer of assets to and from Mantle Network. Those solutions offer higher speed in exchange for different security assumptions.

• Providers such as Stargate and Across offer pooled liquidity and relayer networks which front the destination token balance immediately, thus allowing the user to receive the funds in minutes without the need to wait for a proof.

• The speed of the process depends on a liquidity pool or relayer being available and correctly incentivized to complete the task, thus introducing a different kind of trust than trusting Ethereum for the proof of correctness.

• The official Mantle bridge, however, remains the option with the fewest added trust assumptions, since it relies only on the Mantle and Ethereum contracts plus the underlying proof system, without a third party fronting liquidity.

Choosing between these methods of bridging depends on how urgently the funds are needed on the other side, and on whether the user prefers avoiding the extra security assumptions.

The MNT Token and Mantle's Treasury

MNT is the native token of Mantle Network, used for paying gas fees and participating in governance decisions affecting the protocol. It replaced BIT, the original BitDAO token, as part of the rebrand that created Mantle.

One of the distinctive features of the Mantle ecosystem is its treasury, which is one of the largest among Layer 2s, and comes from BitDAO's initial funding and growth. This treasury allows the project to fund various grant programs, liquidity incentives, and new products built on top of the chain. The Mantle treasury is separate from the bridge itself, though it allowed Mantle to build some part of its ecosystem, such as its liquid staking products (mETH).

Why People Bridge to Mantle

Most users bridge their assets to Mantle to use the decentralized applications built on the platform. Such decentralized exchanges as Merchant Moe and Agni Finance host a significant share of the trading volume on the chain, giving bridged funds somewhere to be swapped or used as liquidity.

Also, Mantle Network supports its own liquid staking products – tokens like mETH (staked ETH that continues earning staking rewards while remaining usable within Mantle's DeFi applications), and cmETH (staked and restaked ETH, which has higher yield compared to regular ETH due to restaking). Minting of these tokens is often one of the reasons why people bridge their ETH to Mantle Network, since it allows keeping the exposure to the staking yield while participating in the DeFi protocols of the Layer 2.

Institutional Products Built on Mantle

Apart from the regular DeFi applications built for retail users, the Mantle ecosystem includes the products built specifically for institutions, namely the index-style investment products, allowing users to gain exposure to multiple digital assets.

These products are developed separately from the Mantle bridge itself. Their growth has become one of the more visible signs of Mantle positioning itself as more than a typical general-purpose Layer 2. The development of the products is partly funded by Mantle's treasury, which is one of the largest among cryptocurrency projects. This does not affect the operation of the bridge itself technically.

How to Use the Mantle Bridge

• Connect a wallet, such as MetaMask, to the official Mantle bridge website.

• Add Mantle Network to the wallet if it is not already configured, using the correct chain ID and RPC endpoint.

• Select the asset and the direction of the transfer.

• Confirm the transaction and pay the required gas fee on the source network.

• For deposits, wait a few minutes for the funds to appear in the destination wallet on Mantle.

• For withdrawals, initiate the withdrawal on Mantle, wait for the validity proof to be verified, and come back to complete the transaction on Ethereum.

Risks and Practical Tips

• Test the bridge with a small amount before using it for the first time or using it with a new wallet.

• Make sure the interface you connect your wallet to is the official one, since fake bridge interfaces are a common phishing target.

• Hold some MNT on Mantle Network to pay gas fees for future transactions.

• Plan ahead for the time of withdrawal, since the transaction is not finalized instantly.