Mantle

Mantle app is a Layer 2 Blockchain Portal for MNT-Powered DeFi

Mantle app is the official Ethereum-to-Mantle bridge interface for moving supported assets from Layer 1 into Mantle Network’s Layer 2 DeFi environment. A deposit starts on Ethereum, so the wallet pays that transaction’s gas in ETH. Once the bridge relays the message, the corresponding balance appears on Mantle, where MNT pays for swaps, approvals and other contract calls. The useful preparation is therefore two-sided: enough ETH to enter and enough MNT to use the deposited asset.

Keep MNT on chain ID 5000 before the deposited asset enters its first DeFi contract.

A deposit from Ethereum to Mantle, step by step

The Mantle deposit workflow is a two-network bridge sequence that begins with an Ethereum signature and ends with a Mantle balance.

Connect and select the pair

Connect MetaMask or another supported EVM wallet. Keep the source set to Ethereum and the destination set to Mantle, then choose an asset exposed by the selector. The app presents two network states even though the account retains the same EVM address. Ethereum Mainnet uses chain ID 1; Mantle Network uses chain ID 5000. Review the token symbol, contract identity and amount before opening the wallet confirmation, because a symbol such as USDC doesn’t by itself identify the chain-specific asset.

Approve an ERC-20 balance

An ETH deposit creates one Ethereum bridge transaction because ETH needs no ERC-20 allowance. A first ERC-20 deposit with no existing allowance creates two L1 transactions: an approval that grants the bridge a spending allowance and the deposit that consumes it. If a previous allowance remains large enough, only the deposit signature returns. Both actions spend ETH for gas; the ERC-20 token itself doesn’t pay the Ethereum execution fee.

Confirm arrival on Mantle

After Ethereum includes the deposit, the bridge relays a cross-layer message and the History view advances through its recorded states. The connected address must be viewed on Mantle to see the destination balance. A completed deposit doesn’t convert the asset into MNT, so reserve MNT separately for the first DeFi approval, swap or lending transaction.

The Mainnet Bridge, Mantle Refuel and Super Portal serve different transfer jobs

The Mainnet Bridge is the canonical Ethereum entry route, while Mantle Refuel and Super Portal address different source assets and destinations. Choose Mainnet Bridge inside Mantle app when the asset starts in an Ethereum wallet and the target is the corresponding Mantle balance. Its cost driver is Ethereum gas, and its dependency is the supported token mapping. It preserves the bridge route’s token identity rather than searching external liquidity for an exchange rate.

Mantle Refuel exists for a narrower problem: acquiring MNT for gas from assets held on another chain. Its interface publishes a $200 single-purchase limit, a fixed operational ceiling rather than a quoted token price. That route matters when a deposit delivers USDC or another asset but leaves the Mantle address unable to pay for the next contract call.

Super Portal connects EVM and Solana wallet environments for cross-chain assets. It isn’t the canonical proof path from Ethereum L1 into Mantle L2, so route selection turns on destination and asset support. Use the Mainnet Bridge for the page’s Ethereum-to-Mantle deposit job, Refuel for MNT gas and Super Portal when the intended route includes Solana.

ETH on L1 and MNT on L2 split the gas bill

The gas split is a two-currency cost model: ETH funds every Ethereum-side signature, while MNT funds execution after arrival on Mantle.

Ethereum-side cost

Ethereum’s fee is gas used multiplied by the effective price per gas. An EIP-1559 type 2 transaction carries both a maximum fee and a priority-fee cap; its envelope begins with transaction-type byte 0x02. A plain ETH transfer has a 21,000-gas intrinsic baseline, but a bridge contract call uses more because it executes calldata and storage changes. Ethereum slots last 12 seconds, and the base fee moves by no more than 12.5% between adjacent blocks. The app’s wallet quote therefore reflects the pending block environment, not a permanent bridge price.

Mantle-side cost

Whatever the setup, Mantle execution charges MNT against the gas consumed by the destination transaction. Mantle v2 Tectonic schedules blocks every 2 seconds, and MNT’s native unit uses 18 decimal places, so one whole MNT contains 10^18 base units. Those constants describe settlement and denomination; the displayed fee still follows the transaction’s gas limit and gas price.

Depositing only the intended DeFi asset creates an unusable balance when the wallet holds zero MNT. Bridge some MNT from Ethereum or acquire it through Mantle Refuel before the first ERC-20 approval.

Can I deposit an ERC-20 token without MNT?

An ERC-20 deposit is an Ethereum-funded bridge action, so the connected wallet needs ETH first and MNT only after the asset reaches Mantle.

Approval and deposit signatures

ERC-20 defines six core token methods and two events, including approve, allowance and transferFrom. The bridge uses that allowance to move the selected amount from the wallet into its L1 custody path. A new allowance adds one transaction before the deposit, making two Ethereum transactions in that first-use path. Later deposits need one transaction when the remaining allowance already covers the selected amount. That sequence stays the same across standard Ethereum ERC-20 bridge deposits.

Approvals encode amounts as uint256 values, a 256-bit unsigned integer type. Wallets convert human units using the token’s declared decimals: Ethereum USDC uses 6 decimals, while MNT uses 18. Entering one displayed token therefore maps to 1,000,000 base units for USDC or 10^18 base units for MNT. Precision is an interface conversion, not a fee.

Token identity after bridging

Token tickers are labels, not unique identifiers across chains. The Mantle interface distinguishes USDT0, its preferred interoperable USDT form, from legacy USDT previously bridged through the canonical route. The interface lists Mantle USDC at 0x09Bc4E0D864854c6aFB6eB9A9cdF58aC190D0dF9. Selecting only a familiar ticker without checking the network and mapped contract can produce a balance that a chosen DeFi market doesn’t accept.

Check the destination app’s accepted contract before depositing. Aave V3, Merchant Moe and Agni Finance each define their own listed markets or pools, so bridge support alone doesn’t establish DeFi support.

Network settings and transaction records that prove arrival

The network record is an on-chain receipt trail that separates Ethereum inclusion, cross-layer relay and the final Mantle balance.

Across most deployments, Mantle Network uses chain ID 5000 and an 18-decimal MNT native balance, while Ethereum Mainnet uses chain ID 1 and ETH for gas.

An EVM address contains 20 bytes, represented as 40 hexadecimal characters or 42 characters after the 0x prefix. The same address text appears on both chains, but each network maintains a separate balance and nonce. A transaction hash contains 32 bytes, normally shown as 64 hexadecimal characters after its prefix. Save the Ethereum deposit hash first; the bridge History view ties it to message progress, while Mantlescan displays the Mantle-side record once relayed. Network selection, not address spelling, determines which ledger the wallet is reading, which is walked through in Using Mantle.

If the app reports completion yet the wallet shows nothing, switch to chain ID 5000 and import the mapped token contract when automatic discovery misses it. The next useful check is the address balance and token transfer record on Mantlescan.

A pre-deposit decision checklist for usable L2 funds

The pre-deposit checklist is a five-condition decision gate that keeps the Ethereum transfer aligned with the first planned Mantle DeFi action.

• Network: the source wallet shows Ethereum Mainnet, chain ID 1, and the destination is Mantle Network, chain ID 5000.
• Gas: enough ETH remains for one native-asset deposit or for both approval and deposit when an ERC-20 allowance is missing.
• Asset mapping: the selector lists the exact source token and the receiving DeFi contract accepts its Mantle representation.
• MNT plan: the destination address will hold an 18-decimal MNT balance before its first approval, swap or lending call.
• Records: the Ethereum hash is saved and History reaches the relayed state before the asset enters another contract.

When all five conditions are true, the deposit arrives as usable working capital rather than an isolated L2 balance. The final choice is operational: bridge MNT with the asset when Ethereum gas is acceptable, or plan Refuel as a separate step. Then connect the same address to the intended Mantle market and confirm that its pool or lending market lists the mapped token before approving any spend.